A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the mai...A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.展开更多
In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide ...In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide application.The efficiency gap between IPSCs and regular structures has shrunk to less than 1%.Over the past few years,IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs.This review provides an overview of recent improvements in the efficiency of IPSCs,including interface engineering and novel film production techniques to overcome critical obstacles.Tandem and integrated applications of IPSCs are also summarized.Furthermore,prospects for further development of IPSCs are discussed,including the development of new materials,methods,and device structures for novel IPSCs to meet the requirements of commercialization.展开更多
Perovskite solar cells(PSCs)have been demonstrated to be one of the most promising technologies in the field of renewable energy.However,the presence of the defects in the perovskite films greatly limits the efficienc...Perovskite solar cells(PSCs)have been demonstrated to be one of the most promising technologies in the field of renewable energy.However,the presence of the defects in the perovskite films greatly limits the efficiency and the stability of the PSCs.The additive engineering is one of the most effective approaches to overcome this problem.Most of the successful additives are extracted from the petroleum-based materials,while the research on the biomass-based additives is still lagging behind.In this paper,two ecofriendly hydroxyalkyl cellulose additives,i.e.,hydroxyethyl cellulose(HEC)and hydroxylpropyl cellulose(HPC),are investigated on the performance of the MAPbl_(3)-based inverted PSCs.Due to the strong interaction between the hydroxyl groups of the cellulose and the divalent cations of the perovskite,these additives enhance the crystal grain orientation and significantly repair the defects of the perovskite films.Working as the additives,these two cellulose derivatives show a strong passivation ability,which significantly reduces the trap density and improves the optoelectronic feature of the PSCs.Compared with the average power conversion efficiency(PCE)of the control device(19.19%),an enhancement of~10%is achieved after the addition of HEC.The optimized device(PCE=21.25%)with a long-term stability(10:80 h,PCE=20.93%)is achieved by the incorporation of the HEC additives into the precursor solution.It is the best performance among the PSCs with the cellulose additives up to now.This research provides a novel choice to develop a cost-effective and renewable additive for the PSCs with high efficiency and excellent long-term stability.展开更多
Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both l...Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both low-cost planar regular and inverted PSCs with excellent efficiencies(>22%)and high stability are very limited.Herein,we employ a novel inorganic ZnSe as ETL for both regular and inverted PSCs to improve the efficiency and stability using a simple thermal evaporation method.The TiO_(2)-ZnSe-FAPbl_(3)heterojunction could be formed,resulting in an improved charge collection and a decreased carrier recombination further proved through theoretical calculations.The optimized regular PSCs based on TiO_(2)/ZnSe have achieved 23.25%efficiency with negligible hysteresis.In addition,the ZnSe ETL can also effectively replace the unstable bathocuproine(BCP)in inverted PSCs.Consequently,the ZnSe-based inverted device realizes a champion efficiency of 22.54%.Moreover,the regular device comprising the TiO_(2)/ZnSe layers retains 92%of its initial PCE after 10:00 h under 1 Sun continuous illumination and the inverted device comprising the C_(60)/ZnSe layers maintains over 85%of its initial PCE at 85℃for 10:00 h.This highlights one of the best results among universal ETLs in both regular and inverted perovskite photovoltaics.展开更多
NiO_(x)-based inverted perovskite solar cells(PSCs)havepresented great potential toward low-cost,highly efficient and stablenext-generation photovoltaics.However,the presence of energy-levelmismatch and contact-interf...NiO_(x)-based inverted perovskite solar cells(PSCs)havepresented great potential toward low-cost,highly efficient and stablenext-generation photovoltaics.However,the presence of energy-levelmismatch and contact-interface defects between hole-selective contacts(HSCs)and perovskite-active layer(PAL)still limits device efficiencyimprovement.Here,we report a graded configuration based on bothinterface-cascaded structures and p-type molecule-doped compositeswith two-/three-dimensional formamidinium-based triple-halideperovskites.We find that the interface defects-induced non-radiativerecombination presented at HSCs/PAL interfaces is remarkably suppressedbecause of efficient hole extraction and transport.Moreover,astrong chemical interaction,halogen bonding and coordination bondingare found in the molecule-doped perovskite composites,whichsignificantly suppress the formation of halide vacancy and parasitic metallic lead.As a result,NiO_(x)-based inverted PSCs present a power-conversion-efficiency over 23%with a high fill factor of 0.84 and open-circuit voltage of 1.162 V,which are comparable to the best reported around 1.56-electron volt bandgap perovskites.Furthermore,devices with encapsulation present high operational stability over 1,200 h during T_(90) lifetime measurement(the time as a function of PCE decreases to 90%of its initial value)under 1-sun illumination in ambient-air conditions.展开更多
Developing high-efficiency and stable inverted CsPbI2Br perovskite solar cells is vitally urgent for their unique advantages of removing adverse dopants and compatible process with tandem cells in comparison with the ...Developing high-efficiency and stable inverted CsPbI2Br perovskite solar cells is vitally urgent for their unique advantages of removing adverse dopants and compatible process with tandem cells in comparison with the regular.However,relatively low opening circuit voltage(Voc)and limited moisture stability have lagged their progress far from the regular.Here,we propose an effective surface treatment strategy with high-temperature FABr treatment to address these issues.The induced ions exchange can not only adjust energy level,but also gift effective passivation.Meanwhile,the gradient distribution of FA+can accelerate the carriers transport to further suppress bulk recombination.Besides,the Br-rich surface and FA+substitution can isolate moisture erosions.As a result,the optimized devices show champion efficiency of 15.92%with Voc of 1.223 V.In addition,the tolerance of humidity and operation get significant promotion:maintaining 91.7%efficiency after aged at RH 20%ambient condition for 1300 h and 81.8%via maximum power point tracking at 45°C for 500 h in N2.Furthermore,the unpackaged devices realize the rare reported air operational stability and,respectively,remain almost efficiency(98.9%)after operated under RH 35%for 600 min and 91.2%under RH 50%for 300 min.展开更多
An inverted structure of polymer solar cells based on Poly(3-hexylthiophene)(P3HT):[6-6] Phenyl-(6) butyric acid methyl ester (PCBM) with using thin films of TiO2 nanotubes and nanoparticles as an efficient c...An inverted structure of polymer solar cells based on Poly(3-hexylthiophene)(P3HT):[6-6] Phenyl-(6) butyric acid methyl ester (PCBM) with using thin films of TiO2 nanotubes and nanoparticles as an efficient cathode buffer layer is developed. A total of three cells employing TiO2 thin films with different thickness values are fabricated. Two cells use layers of TiO2 nanotubes prepared via self-organized electrochemical-anodizing leading to thickness values of 203 and 423.7 nm, while the other cell uses only a simple sol-gel synthesized TiO2 thin film of nanoparticles with a thickness of 100 nm as electron transport layer. Experimental results demonstrate that TiO2 nanotubes with these thickness values are inefficient as the power conversion efficiency of the cell using 100-nm TiO2 thin film is 1.55%, which is more than the best power conversion efficiency of other cells. This can be a result of the weakness of the electrochemical anodizing method to grow nanotubes with lower thickness values. In fact as the TiO2 nanotubes grow in length the series resistance (Rs) between the active polymer layer and electron transport layer increases, meanwhile the fill factor of cells falls dramatically which finally downgrades the power conversion efficiency of the cells as the fill factor falls.展开更多
Inverted perovskite solar cells(IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long...Inverted perovskite solar cells(IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long-term stability issues are the main obstacles that deeply hinder the development of devices. Herein, we demonstrate a facile atomic layer deposition(ALD) processed tin dioxide(SnO2) as an additional buffer layer for efficient and stable wide-bandgap IPSCs. The additional buffer layer increases the shunt resistance and reduces the reverse current saturation density, resulting in the enhancement of efficiency from 19.23% to 21.13%. The target device with a bandgap of 1.63 eV obtains open-circuit voltage of 1.19 V, short circuit current density of 21.86 mA/cm^(2), and fill factor of 81.07%. More importantly, the compact and stable SnO_(2) film invests the IPSCs with superhydrophobicity, thus significantly enhancing the moisture resistance. Eventually, the target device can maintain 90% of its initial efficiency after 600 h storage in ambient conditions with relative humidity of 20%–40% without encapsulation. The ALD-processed SnO_(2) provides a promising way to boost the efficiency and stability of IPSCs, and a great potential for perovskite-based tandem solar cells in the near future.展开更多
We investigated the effects of using different thicknesses of pure and vanadium-doped thin films of TiO2 as the electron transport layer in the inverted configuration of organic photovoltaic cells based on poly(3-hex...We investigated the effects of using different thicknesses of pure and vanadium-doped thin films of TiO2 as the electron transport layer in the inverted configuration of organic photovoltaic cells based on poly(3-hexylthiophene) P3HT:[6-6] phenyl-(6) butyric acid methyl ester(PCBM). 1% vanadium-doped TiO2nanoparticles were synthesized via the solvothermal method. Crystalline structure, morphology, and optical properties of pure and vanadium-doped TiO2 thin films were studied by different techniques such as x-ray diffraction, scanning electron microscopy, transmittance electron microscopy, and UV–visible transmission spectrum. The doctor blade method which is compatible with roll-2-roll printing was used for deposition of pure and vanadium-doped TiO2 thin films with thicknesses of 30 nm and 60 nm. The final results revealed that the best thickness of TiO2 thin films for our fabricated cells was 30 nm. The cell with vanadium-doped TiO2 thin film showed slightly higher power conversion efficiency and great Jsc of 10.7 mA/cm^2 compared with its pure counterpart. In the cells using 60 nm pure and vanadium-doped TiO2 layers, the cell using the doped layer showed much higher efficiency. It is remarkable that the external quantum efficiency of vanadium-doped TiO2 thin film was better in all wavelengths.展开更多
Inverted organic-inorganic hybrid perovskite solar cells(i-PSC)with low temperature processed interlayers and weak hysteresis behaviors have shown great potential for commercialization[1-5].However,their relatively lo...Inverted organic-inorganic hybrid perovskite solar cells(i-PSC)with low temperature processed interlayers and weak hysteresis behaviors have shown great potential for commercialization[1-5].However,their relatively lower power conversion efficiency(PCE)and inferior reproducibility than conventional PSCs limit further developments.These problems are largely determined by the hole transporting layer(HTL)and the quality of the upper perovskite film[6-8];in particular,the latter is considerably influenced by the surface property of the underlying HTL.展开更多
Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unst...Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unstable charge transport layers,such as the hygroscopic doped spiro-OMe TAD,which affect the long-term stability.The inverted device with the p-i-n structure owns better stability when using stable undoped organic molecular or metal oxide materials.There are significant progresses in inverted PSCs,most of them related to charge transport or interface engineering.In this review,we will mainly summarize the inverted PSCs progresses related to the interface engineering.After that,we prospect the future direction on inverted PSCs.展开更多
In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and na...In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and nanorods growth time. Crystalline structure, morphologies, and optical properties of ZnO nanorod arrays are studied by different techniques such as x-ray diffraction, scanning electron microscope, atomic force microscope, and UV-visible transmission spectra. The ZnO nanorod arrays are employed in an inverted bulk heterojunction organic solar cell of Poly (3-hexylthiophene):[6- 6] Phenyl-(6) butyric acid methyl ester to introduce more surface contact between the electron transporter layer and the active layer. Our results show that the deposition time is a very important factor to achieve the aligned and uniform ZnO nanorods with suitable surface density which is required for effective infiltration of active area into the ZnO nanorod spacing and make a maximum interfacial surface contact for electron collection, as overgrowing causes nanorods to be too dense and thick and results in high resistance and lower visible light transmittance. By optimizing the thickness of the active layer on top of ZnO nanorods, an improved efficiency of 3.17% with a high FF beyond 60% was achieved.展开更多
We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte h...We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte hole transport material(P3CT-ED HTM).It is found that P3CT-ED can not only improve the hole transport property of P3CT-K but also improve the crystallinity of adjacent perovskite film.In addition,the introduction of ethanediamine into P3CT realigns the conduction and valence bands upwards,passivates surface defects and reduces nonradiative recombination.As a consequence,compared to P3CT-K hole transport layer(HTL)based devices,the average power conversion efficiency(PCE)is boosted from17.2% to 19.6% for the counterparts with P3CT-ED,with simultaneous enhancement in open circuit voltage and fill factor.The resultant device displays a champion PCE of 20.5% with negligible hysteresis.展开更多
A n-type small molecule DC-IDT2E with 4,4,9,9-tetrakis(4-hexylphenyl)-indaceno[1,2-b:5,6-bt]dithiophene as a central building block, furan as rr-bridges, and 1,1 -dicyanomethylene-3-indanone as end acceptor groups,...A n-type small molecule DC-IDT2E with 4,4,9,9-tetrakis(4-hexylphenyl)-indaceno[1,2-b:5,6-bt]dithiophene as a central building block, furan as rr-bridges, and 1,1 -dicyanomethylene-3-indanone as end acceptor groups, was synthesized and used as an electron acceptor in solution-processed organic solar cells (OSCs). DC-IDT2F exhibited good thermal stability, broad and strong absorption in 500-850 rim, a narrow bandgap of 1.54 eV, LUMO of-3.88 eV, HOMO of-5.44 eV and an electron mobility of 6.5 × 10-4 cm2/(V.s). DC-IDT2F-based OSCs with conventional and inverted structures exhibited power conversion efficiencies of 2.26 and 3.08% respec- tively. The effect of vertical phase separation and morphology of the active layer on the device performance in the two structures was studied.展开更多
A low temperature sol-gel process was used to fabricate zinc-oxide and yttrium-doped zinc oxide layers. These zinc-oxide and yttrium-doped ZnO films were used as electron transport layers in conjunction with P<sub&...A low temperature sol-gel process was used to fabricate zinc-oxide and yttrium-doped zinc oxide layers. These zinc-oxide and yttrium-doped ZnO films were used as electron transport layers in conjunction with P<sub>3</sub>HT and PC<sub>16</sub>BM type solar cells. It was demonstrated that annealing and doping of electron transport layer influenced the overall organic solar cells performance. Anneals of ~ 150?C provided the highest device performance. Compared to the undoped zinc oxide, the device with yttrium doped zinc oxide layers showed improved efficiency by about 30%. Furthermore an equivalent circuit was proposed to understand the connection between the electrical and optical characteristics of the device. Comparisons between the simulated and experimental current-voltage(I-V) curves displayed only a 1.2% variation between the curves. Clearly, our experimental and simulated studies provide new insight on the equivalent circuit models for inverted organic solar cells and further improvement on photovoltaic efficiency.展开更多
Functional additives have recently been regarded as emerging candidates to improve the performance and stability of perovskite solar cells(PSCs).Herein,nicotinamide(N),2-chloronicotinamide(2Cl),and 6-chloronicotinamid...Functional additives have recently been regarded as emerging candidates to improve the performance and stability of perovskite solar cells(PSCs).Herein,nicotinamide(N),2-chloronicotinamide(2Cl),and 6-chloronicotinamide(6Cl)were employed as O-ligands to facilitate the deposition of MAPbI_(3)(MA=methylammonium)and MA-free FA_(0.88)Cs_(0.12)PbI_(2.64)Br_(0.36)(FA=formamidinium)perovskite films by multifunctional anchoring.By density functional theory(DFT)calculations and ultraviolet photoelectron spectroscopy(UPS)measurements,it is identified that the highest occupied molecular orbital(HOMO)level for additive modified MAPbI_(3)perovskite could reduce the voltage deficit for hole extraction.Moreover,due to the most favorable charge distribution and significant improvements in charge mobility and defect passivation,the power conversion efficiency(PCE)of 2Cl-MAPbI_(3)PSCs was significantly improved from 19.32%to 21.12%.More importantly,the two-dimensional grazing-incidence wide-angle X-ray scattering(GIWAXS)analysis showed that PbI_(2) defects were effectively suppressed and femtosecond transient absorption(TA)spectroscopy demonstrated that the trap-assisted recombination at grain boundaries was effectively inhibited in the 2Cl-MA-free film.As a result,the thermally stable 2Cl-MA-free PSCs achieved a remarkable PCE of 23.13%with an open-circuit voltage(V_(oc))of 1.164 V and an ultrahigh fill factor(FF)of 85.7%.Our work offers a practical strategy for further commercializing stable and efficient PSCs.展开更多
High-performance,cost-effective hole-transport materials(HTMs)are greatly desired for the commercialization of perovskite solar cells(PVSCs).Herein,two new HTMs,TPA-FO and TPA-PDO,are devised and synthesized,which hav...High-performance,cost-effective hole-transport materials(HTMs)are greatly desired for the commercialization of perovskite solar cells(PVSCs).Herein,two new HTMs,TPA-FO and TPA-PDO,are devised and synthesized,which have a donor-acceptor-donor(D-A-D)type molecule design featuring carbonyl group-functionalized arenes as the acceptor(A)units.The carbonyl group at the central core of HTMs can not only tune frontier molecular orbital(FMO)energy levels and surface wettability,but also can enable efficient surface passivation effects,resulting in reduced recombination loss.When employed as HTMs in inverted PVSCs without using dopant,TPA-FO with one carbonyl group yields a high power conversion efficiency(PCE)of 20.24%,which is among the highest values reported in the inverted PVSCs with dopant-free HTMs.More importantly,the facile one-step synthetic process enables a low cost of 30 USD g^(-1) for TPA-FO,much cheaper than the most studied HTMs used for high-efficiency dopant-free PVSCs.These results demonstrate the potential of D-A-D type molecules with carbonyl group-functionalized arene core in developing the low-cost dopant-free HTMs toward highly efficient PVSCs.展开更多
The acidic, corrosive effect of sodium polystyrene sulfonate(PSS) in poly 3,4-ethylenedioxythiophene:sodium polystyrene sulfonate(PEDOT:PSS) limits the stability of inverted perovskite solar cells(PSCs) based on the I...The acidic, corrosive effect of sodium polystyrene sulfonate(PSS) in poly 3,4-ethylenedioxythiophene:sodium polystyrene sulfonate(PEDOT:PSS) limits the stability of inverted perovskite solar cells(PSCs) based on the ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag structure. In this work, a poly 3,4-ethylenedioxythiophene(PEDOT) hole transport layer(HTL) with high hole mobility and good catalytic performance was prepared by electrochemical cyclic voltammetry(CV) method for inverted PSCs. By controlling the CV cycles(from 1 to 5 cycles) and EDOT monomer solution concentration(from0.5 to 2.0 mmol·L^(-1)) of electrochemical deposition, the thickness, morphology, optical and electrochemical properties of PEDOT could be accurately adjusted. The optimal photovoltaic performance with current density(J_(sc)) of 22.19 mA·cm^(-2), open circuit voltage(V_(oc)) of 0.94 V, fill factor(FF) of 0.65 and photoelectric conversion efficiency of 13.56% was obtained when deposition of PEDOT with 1 CV cycle and EDOT concentration of 0.5 mmol·L^(-1). At this point, the perovskite showed good crystallization,optimal optical, charge transport and recombination performance, resulting in better V_(oc)and photoelectric conversion efficiency(PCE) compared to the devices with higher CV cycle numbers and 3,4-ethylenedioxythiophene(EDOT) concentration. For comparison with spin-coated PEDOT:PSS, the device with electrodeposited PEDOT showed improved J_(sc)and comparable V_(oc), which may result from its better charge transport and catalytic ability.The device with spin-coated PEDOT:PSS showed photoelectric conversion efficiency of 12.25%, which was lower than that based on electrodeposited PEDOT(13.56%) with1 CV cycles and 0.5 mmol·L^(-1) EDOT concentration. And the device with electrodeposited PEDOT as HTLs showed more excellent air stability. In ambient air((32 ± 5) ℃ and RH: 70% ± 20%), it still maintained more than 80%of the initial photoelectric conversion efficiency after1000 h. In comparison, the photoelectric conversion efficiency of the device with PEDOT:PSS decreased to 20% of the initial value after storage for 500 h. From this study, a facial and low-cost way to prepare PEDOT HTL with high performances that better than the traditional PEDOT:PSS has been explored, which is expected to eliminate the acidic, corrosive effect of PSS in PEDOT:PSS.展开更多
Although many dopant-free hole transport materials(HTMs)for perovskite solar cells(PSCs)have been investigated in the literature,novel and useful molecular designs for high-performance HTMs are still needed.In this wo...Although many dopant-free hole transport materials(HTMs)for perovskite solar cells(PSCs)have been investigated in the literature,novel and useful molecular designs for high-performance HTMs are still needed.In this work,a hydrogen-bonding association system(NH⋯CO)between amide and carbonyl is introduced into the pure HTM layer.展开更多
Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butyl...Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine])have been widely adopted as hole-transport materials due to their perovskite passivation effects and suitable energy levels.However,the passivation mechanism(i.e.,the functional group responsible for perovskite passivation)of triphenylamine derivative polymers remains unclear,hindering the development and application of this polymer type.Here,we develop a novel Poly-TPD derivative,S-Poly-TPD,by replacing the n-butyl functional group of Poly-TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top-deposited perovskite properties.Compared with Poly-TPD,the increased CH_(3)-terminal unit density and the decreased spatial distance between the-CH-CH_(3) and-CH_(2)-CH_(3) units and the benzene ring in S-Poly-TPD not only enhanced the hole-transport ability but also improved the perovskite passivation effect,revealing for the first time the role of the alkyl groups in perovskite passivation.As a result,the S-Poly-TPD-based IPVSCs demonstrated high power-conversion efficiencies of 15.1% and 21.3% in wide-bandgap[MAPbI_(2)Br(SCN)0.12]and normal-bandgap[(FAPbI_(3))0.92(MAPbBr_(3))0.08]devices,respectively.展开更多
基金the financial support from Shanxi Province Science and Technology Department(20201101012,202101060301016)the support from the APRC Grant of the City University of Hong Kong(9380086)+5 种基金the TCFS Grant(GHP/018/20SZ)MRP Grant(MRP/040/21X)from the Innovation and Technology Commission of Hong Kongthe Green Tech Fund(202020164)from the Environment and Ecology Bureau of Hong Kongthe GRF grants(11307621,11316422)from the Research Grants Council of Hong KongGuangdong Major Project of Basic and Applied Basic Research(2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002).
文摘A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.
基金the Research Grants Council of Hong Kong(GRF Grant Nos.15221320,CRF C7018-20G)the Shenzhen Science and Technology Innovation Commission(Project No.JCYJ 20200109105003940,SGDX20201103095403016)+6 种基金the Hong Kong Innovation and Technology Commission(GHP/205/20SZ)the Sir Sze-yuen Chung Endowed Professorship Fund(8-8480)provided by the Hong Kong Polytechnic Universitythe GuangdongHong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices(GDSTC No.2019B121205001)the National Natural Science Foundation of China(Grant No.91963129)the Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(Grant No.2018B030322001)the Student Innovation Training Program(Grant Nos.2021S07)from Southern University of Science and Technology(SUSTech)the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(pdjh2022c0003&pdjh2022c0005)。
文摘In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide application.The efficiency gap between IPSCs and regular structures has shrunk to less than 1%.Over the past few years,IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs.This review provides an overview of recent improvements in the efficiency of IPSCs,including interface engineering and novel film production techniques to overcome critical obstacles.Tandem and integrated applications of IPSCs are also summarized.Furthermore,prospects for further development of IPSCs are discussed,including the development of new materials,methods,and device structures for novel IPSCs to meet the requirements of commercialization.
基金the National Natural Science Foundation of China(61935017,62175268,21674123,31700507)Fujian Natural Science Foundation for Distinguished Young Scholars(2020J06039)+4 种基金Project of“100 People Planning in Fujian Province,”Fujian Provincial Department of Finance for the research of organic photovoltaic solar cell(Kle20001A)the Science and Technology Development Fund,Macao SAR(File no.FDCT-0044/2020/A1,0082/2021/A2)UM's research fund(File no.MYRG2020-00151-IAPME)Natural Science Foundation of Guangdong Province,China(2019A1515012186)Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C)(SGDX2020110309360100).
文摘Perovskite solar cells(PSCs)have been demonstrated to be one of the most promising technologies in the field of renewable energy.However,the presence of the defects in the perovskite films greatly limits the efficiency and the stability of the PSCs.The additive engineering is one of the most effective approaches to overcome this problem.Most of the successful additives are extracted from the petroleum-based materials,while the research on the biomass-based additives is still lagging behind.In this paper,two ecofriendly hydroxyalkyl cellulose additives,i.e.,hydroxyethyl cellulose(HEC)and hydroxylpropyl cellulose(HPC),are investigated on the performance of the MAPbl_(3)-based inverted PSCs.Due to the strong interaction between the hydroxyl groups of the cellulose and the divalent cations of the perovskite,these additives enhance the crystal grain orientation and significantly repair the defects of the perovskite films.Working as the additives,these two cellulose derivatives show a strong passivation ability,which significantly reduces the trap density and improves the optoelectronic feature of the PSCs.Compared with the average power conversion efficiency(PCE)of the control device(19.19%),an enhancement of~10%is achieved after the addition of HEC.The optimized device(PCE=21.25%)with a long-term stability(10:80 h,PCE=20.93%)is achieved by the incorporation of the HEC additives into the precursor solution.It is the best performance among the PSCs with the cellulose additives up to now.This research provides a novel choice to develop a cost-effective and renewable additive for the PSCs with high efficiency and excellent long-term stability.
基金supported by the Solar Energy Research Institute of Singapore(SERIS)at the National University of Singapore(NUS).SERIS is supported by NUS,the National Research Foundation Singapore(NRF),the Energy Market Authority of Singapore(EMA),and the Singapore Economic Development Board(EDB)support from the Science and Engineering Research Council of Singapore with Grant No.A1898b0043Singapore NRF CRP Grant No.NRF-CRP24-2020-0002.
文摘Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both low-cost planar regular and inverted PSCs with excellent efficiencies(>22%)and high stability are very limited.Herein,we employ a novel inorganic ZnSe as ETL for both regular and inverted PSCs to improve the efficiency and stability using a simple thermal evaporation method.The TiO_(2)-ZnSe-FAPbl_(3)heterojunction could be formed,resulting in an improved charge collection and a decreased carrier recombination further proved through theoretical calculations.The optimized regular PSCs based on TiO_(2)/ZnSe have achieved 23.25%efficiency with negligible hysteresis.In addition,the ZnSe ETL can also effectively replace the unstable bathocuproine(BCP)in inverted PSCs.Consequently,the ZnSe-based inverted device realizes a champion efficiency of 22.54%.Moreover,the regular device comprising the TiO_(2)/ZnSe layers retains 92%of its initial PCE after 10:00 h under 1 Sun continuous illumination and the inverted device comprising the C_(60)/ZnSe layers maintains over 85%of its initial PCE at 85℃for 10:00 h.This highlights one of the best results among universal ETLs in both regular and inverted perovskite photovoltaics.
基金supported by National Natural Science Foundation of China (62204099)Guangdong Basic and Applied Basic Research Foundation (2020A1515110462)+1 种基金Fundamental Research Funds for the Central Universities (21620347)the Special Funds for College Students’ Innovative Entrepreneurial Training Plan Program
文摘NiO_(x)-based inverted perovskite solar cells(PSCs)havepresented great potential toward low-cost,highly efficient and stablenext-generation photovoltaics.However,the presence of energy-levelmismatch and contact-interface defects between hole-selective contacts(HSCs)and perovskite-active layer(PAL)still limits device efficiencyimprovement.Here,we report a graded configuration based on bothinterface-cascaded structures and p-type molecule-doped compositeswith two-/three-dimensional formamidinium-based triple-halideperovskites.We find that the interface defects-induced non-radiativerecombination presented at HSCs/PAL interfaces is remarkably suppressedbecause of efficient hole extraction and transport.Moreover,astrong chemical interaction,halogen bonding and coordination bondingare found in the molecule-doped perovskite composites,whichsignificantly suppress the formation of halide vacancy and parasitic metallic lead.As a result,NiO_(x)-based inverted PSCs present a power-conversion-efficiency over 23%with a high fill factor of 0.84 and open-circuit voltage of 1.162 V,which are comparable to the best reported around 1.56-electron volt bandgap perovskites.Furthermore,devices with encapsulation present high operational stability over 1,200 h during T_(90) lifetime measurement(the time as a function of PCE decreases to 90%of its initial value)under 1-sun illumination in ambient-air conditions.
基金The authors thank the financial supports by the National Natural Science Foundation of China(61974150 and 51773213)the Zhejiang Provincial Natural Science Foundation of China(LQ19E030008)+1 种基金the Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-JSC047),the Zhejiang Province Science and Technology Plan(2018C01047)the Fundamental Research Funds for the Central Universities and the National Youth Top-notch Talent Support Program.
文摘Developing high-efficiency and stable inverted CsPbI2Br perovskite solar cells is vitally urgent for their unique advantages of removing adverse dopants and compatible process with tandem cells in comparison with the regular.However,relatively low opening circuit voltage(Voc)and limited moisture stability have lagged their progress far from the regular.Here,we propose an effective surface treatment strategy with high-temperature FABr treatment to address these issues.The induced ions exchange can not only adjust energy level,but also gift effective passivation.Meanwhile,the gradient distribution of FA+can accelerate the carriers transport to further suppress bulk recombination.Besides,the Br-rich surface and FA+substitution can isolate moisture erosions.As a result,the optimized devices show champion efficiency of 15.92%with Voc of 1.223 V.In addition,the tolerance of humidity and operation get significant promotion:maintaining 91.7%efficiency after aged at RH 20%ambient condition for 1300 h and 81.8%via maximum power point tracking at 45°C for 500 h in N2.Furthermore,the unpackaged devices realize the rare reported air operational stability and,respectively,remain almost efficiency(98.9%)after operated under RH 35%for 600 min and 91.2%under RH 50%for 300 min.
文摘An inverted structure of polymer solar cells based on Poly(3-hexylthiophene)(P3HT):[6-6] Phenyl-(6) butyric acid methyl ester (PCBM) with using thin films of TiO2 nanotubes and nanoparticles as an efficient cathode buffer layer is developed. A total of three cells employing TiO2 thin films with different thickness values are fabricated. Two cells use layers of TiO2 nanotubes prepared via self-organized electrochemical-anodizing leading to thickness values of 203 and 423.7 nm, while the other cell uses only a simple sol-gel synthesized TiO2 thin film of nanoparticles with a thickness of 100 nm as electron transport layer. Experimental results demonstrate that TiO2 nanotubes with these thickness values are inefficient as the power conversion efficiency of the cell using 100-nm TiO2 thin film is 1.55%, which is more than the best power conversion efficiency of other cells. This can be a result of the weakness of the electrochemical anodizing method to grow nanotubes with lower thickness values. In fact as the TiO2 nanotubes grow in length the series resistance (Rs) between the active polymer layer and electron transport layer increases, meanwhile the fill factor of cells falls dramatically which finally downgrades the power conversion efficiency of the cells as the fill factor falls.
基金the supports from National Key Research and Development Program of China(Grant No.2018YFB1500103)the Overseas Expertise Introduction Project for Discipline Innovation of Higher Education of China(Grant No.B16027)+3 种基金Tianjin Science and Technology Project(Grant No.18ZXJMTG00220)the Fundamental Research Funds for the Central Universities,Nankai University(Grant Nos.63191736,ZB19500204)Natural Science Foundation of Tianjin(No.20JCQNJC02070)China Postdoctoral Scie nce Foundation(No.2020T130317)。
文摘Inverted perovskite solar cells(IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long-term stability issues are the main obstacles that deeply hinder the development of devices. Herein, we demonstrate a facile atomic layer deposition(ALD) processed tin dioxide(SnO2) as an additional buffer layer for efficient and stable wide-bandgap IPSCs. The additional buffer layer increases the shunt resistance and reduces the reverse current saturation density, resulting in the enhancement of efficiency from 19.23% to 21.13%. The target device with a bandgap of 1.63 eV obtains open-circuit voltage of 1.19 V, short circuit current density of 21.86 mA/cm^(2), and fill factor of 81.07%. More importantly, the compact and stable SnO_(2) film invests the IPSCs with superhydrophobicity, thus significantly enhancing the moisture resistance. Eventually, the target device can maintain 90% of its initial efficiency after 600 h storage in ambient conditions with relative humidity of 20%–40% without encapsulation. The ALD-processed SnO_(2) provides a promising way to boost the efficiency and stability of IPSCs, and a great potential for perovskite-based tandem solar cells in the near future.
文摘We investigated the effects of using different thicknesses of pure and vanadium-doped thin films of TiO2 as the electron transport layer in the inverted configuration of organic photovoltaic cells based on poly(3-hexylthiophene) P3HT:[6-6] phenyl-(6) butyric acid methyl ester(PCBM). 1% vanadium-doped TiO2nanoparticles were synthesized via the solvothermal method. Crystalline structure, morphology, and optical properties of pure and vanadium-doped TiO2 thin films were studied by different techniques such as x-ray diffraction, scanning electron microscopy, transmittance electron microscopy, and UV–visible transmission spectrum. The doctor blade method which is compatible with roll-2-roll printing was used for deposition of pure and vanadium-doped TiO2 thin films with thicknesses of 30 nm and 60 nm. The final results revealed that the best thickness of TiO2 thin films for our fabricated cells was 30 nm. The cell with vanadium-doped TiO2 thin film showed slightly higher power conversion efficiency and great Jsc of 10.7 mA/cm^2 compared with its pure counterpart. In the cells using 60 nm pure and vanadium-doped TiO2 layers, the cell using the doped layer showed much higher efficiency. It is remarkable that the external quantum efficiency of vanadium-doped TiO2 thin film was better in all wavelengths.
基金financially supported by the Research Grants Council of Hong Kong(GRF grant 15246816 and CRF grant C5037-18G)Shenzhen Science and Technology Innovation Commission(Project No.JCYJ20170413154602102)+4 种基金LiaoNing Revitalization Talents Program(XLYC1807231)the DICP ZZBS201813the Natural Science Foundation of Liaoning Province of China(20180540124)the Hong Kong Polytechnic University internal research fundsthe support of Hong Kong Scholars Program(XJ2017046)。
文摘Inverted organic-inorganic hybrid perovskite solar cells(i-PSC)with low temperature processed interlayers and weak hysteresis behaviors have shown great potential for commercialization[1-5].However,their relatively lower power conversion efficiency(PCE)and inferior reproducibility than conventional PSCs limit further developments.These problems are largely determined by the hole transporting layer(HTL)and the quality of the upper perovskite film[6-8];in particular,the latter is considerably influenced by the surface property of the underlying HTL.
基金supported by the National Natural Science Foundation of China(Grant No.61925405)the National Key Research and Development Program of China(Grant No.2020YFB1506400)。
文摘Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unstable charge transport layers,such as the hygroscopic doped spiro-OMe TAD,which affect the long-term stability.The inverted device with the p-i-n structure owns better stability when using stable undoped organic molecular or metal oxide materials.There are significant progresses in inverted PSCs,most of them related to charge transport or interface engineering.In this review,we will mainly summarize the inverted PSCs progresses related to the interface engineering.After that,we prospect the future direction on inverted PSCs.
文摘In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and nanorods growth time. Crystalline structure, morphologies, and optical properties of ZnO nanorod arrays are studied by different techniques such as x-ray diffraction, scanning electron microscope, atomic force microscope, and UV-visible transmission spectra. The ZnO nanorod arrays are employed in an inverted bulk heterojunction organic solar cell of Poly (3-hexylthiophene):[6- 6] Phenyl-(6) butyric acid methyl ester to introduce more surface contact between the electron transporter layer and the active layer. Our results show that the deposition time is a very important factor to achieve the aligned and uniform ZnO nanorods with suitable surface density which is required for effective infiltration of active area into the ZnO nanorod spacing and make a maximum interfacial surface contact for electron collection, as overgrowing causes nanorods to be too dense and thick and results in high resistance and lower visible light transmittance. By optimizing the thickness of the active layer on top of ZnO nanorods, an improved efficiency of 3.17% with a high FF beyond 60% was achieved.
基金supported by the National Natural Science Foundation of China(51672288,21975273)Taishan Scholars Program of Shandong Province,Dalian National Laboratory for Clean Energy(DICP&QIBEBT No.UN201705)+1 种基金Scientific Research Cooperation Foundation of Qingdao Institute of Bioenergy and Bioprocess TechnologyQingdao Postdoctoral Application Research Project(Project 2018183,2018186)。
文摘We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells(PSCs)by using small molecule ethanediamine for the construction of a novel polyelectrolyte hole transport material(P3CT-ED HTM).It is found that P3CT-ED can not only improve the hole transport property of P3CT-K but also improve the crystallinity of adjacent perovskite film.In addition,the introduction of ethanediamine into P3CT realigns the conduction and valence bands upwards,passivates surface defects and reduces nonradiative recombination.As a consequence,compared to P3CT-K hole transport layer(HTL)based devices,the average power conversion efficiency(PCE)is boosted from17.2% to 19.6% for the counterparts with P3CT-ED,with simultaneous enhancement in open circuit voltage and fill factor.The resultant device displays a champion PCE of 20.5% with negligible hysteresis.
基金supported by the National Natural Science Foundation of China(91433114,51261130582,21025418)the 973 Program(2011CB808401)the Chinese Academy of Sciences
文摘A n-type small molecule DC-IDT2E with 4,4,9,9-tetrakis(4-hexylphenyl)-indaceno[1,2-b:5,6-bt]dithiophene as a central building block, furan as rr-bridges, and 1,1 -dicyanomethylene-3-indanone as end acceptor groups, was synthesized and used as an electron acceptor in solution-processed organic solar cells (OSCs). DC-IDT2F exhibited good thermal stability, broad and strong absorption in 500-850 rim, a narrow bandgap of 1.54 eV, LUMO of-3.88 eV, HOMO of-5.44 eV and an electron mobility of 6.5 × 10-4 cm2/(V.s). DC-IDT2F-based OSCs with conventional and inverted structures exhibited power conversion efficiencies of 2.26 and 3.08% respec- tively. The effect of vertical phase separation and morphology of the active layer on the device performance in the two structures was studied.
文摘A low temperature sol-gel process was used to fabricate zinc-oxide and yttrium-doped zinc oxide layers. These zinc-oxide and yttrium-doped ZnO films were used as electron transport layers in conjunction with P<sub>3</sub>HT and PC<sub>16</sub>BM type solar cells. It was demonstrated that annealing and doping of electron transport layer influenced the overall organic solar cells performance. Anneals of ~ 150?C provided the highest device performance. Compared to the undoped zinc oxide, the device with yttrium doped zinc oxide layers showed improved efficiency by about 30%. Furthermore an equivalent circuit was proposed to understand the connection between the electrical and optical characteristics of the device. Comparisons between the simulated and experimental current-voltage(I-V) curves displayed only a 1.2% variation between the curves. Clearly, our experimental and simulated studies provide new insight on the equivalent circuit models for inverted organic solar cells and further improvement on photovoltaic efficiency.
基金This work was financially supported by the National Natural Science Foundation of China(51702038,U21A20331,51773212 and 81903743)the Sichuan Science&Technology Program(2020YFG0061)+1 种基金National Science Fund for Distinguished Young Scholars(21925506)Natural Science Foundation of Ningbo(2021J192).
文摘Functional additives have recently been regarded as emerging candidates to improve the performance and stability of perovskite solar cells(PSCs).Herein,nicotinamide(N),2-chloronicotinamide(2Cl),and 6-chloronicotinamide(6Cl)were employed as O-ligands to facilitate the deposition of MAPbI_(3)(MA=methylammonium)and MA-free FA_(0.88)Cs_(0.12)PbI_(2.64)Br_(0.36)(FA=formamidinium)perovskite films by multifunctional anchoring.By density functional theory(DFT)calculations and ultraviolet photoelectron spectroscopy(UPS)measurements,it is identified that the highest occupied molecular orbital(HOMO)level for additive modified MAPbI_(3)perovskite could reduce the voltage deficit for hole extraction.Moreover,due to the most favorable charge distribution and significant improvements in charge mobility and defect passivation,the power conversion efficiency(PCE)of 2Cl-MAPbI_(3)PSCs was significantly improved from 19.32%to 21.12%.More importantly,the two-dimensional grazing-incidence wide-angle X-ray scattering(GIWAXS)analysis showed that PbI_(2) defects were effectively suppressed and femtosecond transient absorption(TA)spectroscopy demonstrated that the trap-assisted recombination at grain boundaries was effectively inhibited in the 2Cl-MA-free film.As a result,the thermally stable 2Cl-MA-free PSCs achieved a remarkable PCE of 23.13%with an open-circuit voltage(V_(oc))of 1.164 V and an ultrahigh fill factor(FF)of 85.7%.Our work offers a practical strategy for further commercializing stable and efficient PSCs.
基金the National Natural Science Foundation of China(NSFC,No.21801124)X.G.is grateful to the Shenzhen Science and Technology Innovation Commission(No.JCYJ20180504165709042)We are grateful for the assistance of SUSTech Core Research Facilities.PL and TRPL characterizations were supported by Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation(FSSEG)from the Shenzhen Key Laboratory Project(No.ZDSYS201602261933302).
文摘High-performance,cost-effective hole-transport materials(HTMs)are greatly desired for the commercialization of perovskite solar cells(PVSCs).Herein,two new HTMs,TPA-FO and TPA-PDO,are devised and synthesized,which have a donor-acceptor-donor(D-A-D)type molecule design featuring carbonyl group-functionalized arenes as the acceptor(A)units.The carbonyl group at the central core of HTMs can not only tune frontier molecular orbital(FMO)energy levels and surface wettability,but also can enable efficient surface passivation effects,resulting in reduced recombination loss.When employed as HTMs in inverted PVSCs without using dopant,TPA-FO with one carbonyl group yields a high power conversion efficiency(PCE)of 20.24%,which is among the highest values reported in the inverted PVSCs with dopant-free HTMs.More importantly,the facile one-step synthetic process enables a low cost of 30 USD g^(-1) for TPA-FO,much cheaper than the most studied HTMs used for high-efficiency dopant-free PVSCs.These results demonstrate the potential of D-A-D type molecules with carbonyl group-functionalized arene core in developing the low-cost dopant-free HTMs toward highly efficient PVSCs.
基金financially supported by the National Natural Science Foundation of China(No.61774169)Qingyuan Innovation and Entrepreneurship Research Team Project(No.2018001)。
文摘The acidic, corrosive effect of sodium polystyrene sulfonate(PSS) in poly 3,4-ethylenedioxythiophene:sodium polystyrene sulfonate(PEDOT:PSS) limits the stability of inverted perovskite solar cells(PSCs) based on the ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag structure. In this work, a poly 3,4-ethylenedioxythiophene(PEDOT) hole transport layer(HTL) with high hole mobility and good catalytic performance was prepared by electrochemical cyclic voltammetry(CV) method for inverted PSCs. By controlling the CV cycles(from 1 to 5 cycles) and EDOT monomer solution concentration(from0.5 to 2.0 mmol·L^(-1)) of electrochemical deposition, the thickness, morphology, optical and electrochemical properties of PEDOT could be accurately adjusted. The optimal photovoltaic performance with current density(J_(sc)) of 22.19 mA·cm^(-2), open circuit voltage(V_(oc)) of 0.94 V, fill factor(FF) of 0.65 and photoelectric conversion efficiency of 13.56% was obtained when deposition of PEDOT with 1 CV cycle and EDOT concentration of 0.5 mmol·L^(-1). At this point, the perovskite showed good crystallization,optimal optical, charge transport and recombination performance, resulting in better V_(oc)and photoelectric conversion efficiency(PCE) compared to the devices with higher CV cycle numbers and 3,4-ethylenedioxythiophene(EDOT) concentration. For comparison with spin-coated PEDOT:PSS, the device with electrodeposited PEDOT showed improved J_(sc)and comparable V_(oc), which may result from its better charge transport and catalytic ability.The device with spin-coated PEDOT:PSS showed photoelectric conversion efficiency of 12.25%, which was lower than that based on electrodeposited PEDOT(13.56%) with1 CV cycles and 0.5 mmol·L^(-1) EDOT concentration. And the device with electrodeposited PEDOT as HTLs showed more excellent air stability. In ambient air((32 ± 5) ℃ and RH: 70% ± 20%), it still maintained more than 80%of the initial photoelectric conversion efficiency after1000 h. In comparison, the photoelectric conversion efficiency of the device with PEDOT:PSS decreased to 20% of the initial value after storage for 500 h. From this study, a facial and low-cost way to prepare PEDOT HTL with high performances that better than the traditional PEDOT:PSS has been explored, which is expected to eliminate the acidic, corrosive effect of PSS in PEDOT:PSS.
基金from the Natural Science Foundation of China(grant no.21805151)the Natural Science Foundation of Shandong Province,China(grant no.ZR2018MB024)and the Young Taishan Scholars(grant nos.201909120 and 201909121).M.L.acknowledges the Finnish Cultural Foundation(no.00210670)for funding.P.V.thanks the Jane and Aatos Erkko foundation(project ASPIRE)for financial support.This work is part of the Academy of Finland Flagship Programme,Photonics Research and Innovation(PREIN),Decision No.320165.
文摘Although many dopant-free hole transport materials(HTMs)for perovskite solar cells(PSCs)have been investigated in the literature,novel and useful molecular designs for high-performance HTMs are still needed.In this work,a hydrogen-bonding association system(NH⋯CO)between amide and carbonyl is introduced into the pure HTM layer.
基金The work was financially supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2019B030302007)the Ministry of Science and Technology(Nos.2017YFA0206600,2019YFA 0705900)+3 种基金the Natural Science Foundation of China(Nos.51973063,91733302 and 51803060)the Science and Technology Program of Guangdong Province,China(No.2018A030313045)the Science and Technology Program of Guangzhou,China(No.201904010147).Yue‐Min Xie acknowledged the funding by State Key Lab of Luminescent Materials and Devices,South China Uni-versity of Technology,the Fellowship of China Post-doctoral Science Foundation(No.2020M682703)the National Natural Science Foundation of China(No.52003090).
文摘Polymer hole-transport layers(HTLs)are critical components of inverted perovskite solar cells(IPVSCs).Triphenylamine derivatives PTAA(poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine])and Poly-TPD(poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine])have been widely adopted as hole-transport materials due to their perovskite passivation effects and suitable energy levels.However,the passivation mechanism(i.e.,the functional group responsible for perovskite passivation)of triphenylamine derivative polymers remains unclear,hindering the development and application of this polymer type.Here,we develop a novel Poly-TPD derivative,S-Poly-TPD,by replacing the n-butyl functional group of Poly-TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top-deposited perovskite properties.Compared with Poly-TPD,the increased CH_(3)-terminal unit density and the decreased spatial distance between the-CH-CH_(3) and-CH_(2)-CH_(3) units and the benzene ring in S-Poly-TPD not only enhanced the hole-transport ability but also improved the perovskite passivation effect,revealing for the first time the role of the alkyl groups in perovskite passivation.As a result,the S-Poly-TPD-based IPVSCs demonstrated high power-conversion efficiencies of 15.1% and 21.3% in wide-bandgap[MAPbI_(2)Br(SCN)0.12]and normal-bandgap[(FAPbI_(3))0.92(MAPbBr_(3))0.08]devices,respectively.