To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adeq...To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.展开更多
Coper thiocyanate(CuSCN)is generally considered as a very hopeful inorganic hole transport material(HTM)in semitransparent perovskite solar cells(ST-PSCs)because of its low parasitic absorption,high inherent stability...Coper thiocyanate(CuSCN)is generally considered as a very hopeful inorganic hole transport material(HTM)in semitransparent perovskite solar cells(ST-PSCs)because of its low parasitic absorption,high inherent stability,and low cost.However,the poor electrical conductivity and low work function of CuSCN lead to the insufficient hole extraction and large open-circuit voltage loss.Here,2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4TCNQ)is employed to improve conductivity of CuSCN and band alignment at the CuSCN/perovskite(PVK)interface.As a result,the average power conversion efficiency(PCE)of PSCs is boosted by≈11%.In addition,benefiting from the superior transparency of p-type CuSCN HTMs,the prepared bifacial semitransparent n-i-p planar PSCs demonstrate a maximum efficiency of 14.8%and 12.5%by the illumination from the front side and back side,respectively.We believe that this developed CuSCN-based ST-PSCs will promote practical applications in building integrated photovoltaics and tandem solar cells.展开更多
Perovskite solar cells(PSCs) are the most promising commercial photoelectric conversion technology in the future.The planar p–i–n structure cells have advantages in negligible hysteresis, low temperature preparation...Perovskite solar cells(PSCs) are the most promising commercial photoelectric conversion technology in the future.The planar p–i–n structure cells have advantages in negligible hysteresis, low temperature preparation and excellent stability.However, for inverted planar PSCs, the non-radiative recombination at the interface is an important reason that impedes the charge transfer and improvement of power conversion efficiency. Having a homogeneous, compact, and energy-levelmatched charge transport layer is the key to reducing non-radiative recombination. In our study, NiO_(x)/Sr:NiO_(x)bilayer hole transport layer(HTL) improves the holes transmission of NiO_(x)based HTL, reduces the recombination in the interface between perovskite and HTL layer and improves the device performance. The bilayer HTL enhances the hole transfer by forming a driving force of an electric field and further improves J_(sc). As a result, the device has a power conversion efficiency of 18.44%, a short circuit current density of 22.81 m A·cm^(-2) and a fill factor of 0.80. Compared to the pristine PSCs, there are certain improvements of optical parameters. This method provides a new idea for the future design of novel hole transport layers and the development of high-performance solar cells.展开更多
We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigati...We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.展开更多
We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine (ZnPc)-based composite hole transport layer (c-HTL). The optim...We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine (ZnPc)-based composite hole transport layer (c-HTL). The optimum ris-(8-hydroxyquinoline)aluminum (Alq3)-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device (turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W). We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis(1-naphthyl)(1,1’-biphenyl)-4,4’diamine (NPB):ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.展开更多
Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7...Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is unstable at elevated temperatures and high humidity.In this work,aπ-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)](PBDB-T)is selected to form a polymer composite hole transport layer(HTL)with Spiro-OMeTAD.The sulfur atom of the thiophene unit and the carbonyl group of the polymer interact with the undercoordinated Pb2+at the perovskite surface,which stabilizes the perovskite/HTL interface and passivates the interfacial defects.The incorporation of the polymer also increases the glass transition temperature and the moisture resistance of Spiro-OMeTAD.As a result,we obtain ST-PSCs with a champion efficiency of 13.71%and an average visible light transmittance of 36.04%.Therefore,a high light utilization efficiency of 4.94%can be obtained.Moreover,the encapsulated device can maintain 84%of the initial efficiency after 751 h under continuous one-sun illumination(at 30%relative humidity)at the open circuit and the unencapsulated device can maintain 80%of the initial efficiency after maximum power tracking for more than 1250 h under continuous one-sun illumination.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
In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The p...In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The power conversion efficiency has rapidly increased by more than 6 times to the current 25.5% in the past decade. Hole transport materials (HTMs) are an indispensable part of PSCs, which great affect the efficiency, the cost and the stability of PSCs. Inorganic Cu-based p-type semiconductors are a kind of representative inorganic HTMs in PSCs due to their unique advantages of rich variety, low cost, excellent hole mobility, adjustable energy levels, good stability, low temperature and scalable processing ability. In this review, the research progress in new materials and the control of photoelectric properties of Cu-based inorganic HTMs were first summarized systematically. And then, concerning different processing methods, advances of the interface engineering of Cu-based hole transport layers (HTLs) in PSCs were detailly discussed. Finally, the challenges and future trends of Cu-based inorganic HTMs and their interface engineering in PSCs were analyzed.展开更多
The silicon heterojunction(SHJ)solar cell has long been considered as one of the most promising candidates for the next-generation PV market.Transition metal oxides(TMOs)show good carrier selectivity when combined wit...The silicon heterojunction(SHJ)solar cell has long been considered as one of the most promising candidates for the next-generation PV market.Transition metal oxides(TMOs)show good carrier selectivity when combined with c-Si solar cells.This has led to the rapid demonstration of the remarkable potential of TMOs(especially MoO_(x))with high work function to replace the p-type a-Si:H emitting layer.MoO_(x) can induce a strong inversion layer on the interface of n-type c-Si,which is beneficial to the extraction and conduction of holes.In this paper,the radio-frequency(RF)magnetron sputtering is used to deposit MoO_(x) films.The optical,electrical and structural properties of MoO_(x) films are measured and analyzed,with focus on the inherent compositions and work function.Then the MoO_(x) films are applied into SHJ solar cells.When the MoO_(x) works as a buffer layer between ITO/p-a-Si:H interface in the reference SHJ solar cell,a conversion efficiency of 19.1%can be obtained.When the MoOx is used as a hole transport layer(HTL),the device indicates a desirable conversion efficiency of 17.5%.To the best of our knowledge,this current efficiency is the highest one for the MoO_(x) film as HTL by RF sputtering.展开更多
This report presents two non-perihperally octaalkyl-substituted nickel phthalocyanines(NiPcs),namely,NiEt2Pc and NiPr_(2)Pc,for use as dopant-free hole transport materials in perovskite solar cells(PSCs).The length ex...This report presents two non-perihperally octaalkyl-substituted nickel phthalocyanines(NiPcs),namely,NiEt2Pc and NiPr_(2)Pc,for use as dopant-free hole transport materials in perovskite solar cells(PSCs).The length extension of the alkyl chains from ethyl to propyl significantly tunes the NiPcs’energy levels,thus reducing charge carrier recombination at the perovskite/hole transport layer(HTL)interface and leading to higher open-circuit voltage(VOC)and short-circuit current density(JSC)observed for the NiPr_(2)Pc-based PSC.And higher charge carrier mobility,higher thin film crystallinity,and lower surface roughness of the NiPr_(2)Pc HTL compared with that of the NiEt2Pc one also lead to higher JSC and fill factor(FF)observed for the NiPr_(2)Pc-based device.Consequently,the NiPr_(2)Pc-based PSC exhibits a higher power conversion efficiency(PCE)of 14.07%than that of the NiEt2Pc-based device(8.63%).展开更多
The hole transport layer(HTL)affects the device performance and stability of organic solar cells.In this work,a stable molybdenum oxide(MoO_(x))hole transport layer with low cost was prepared by adjusting the state of...The hole transport layer(HTL)affects the device performance and stability of organic solar cells.In this work,a stable molybdenum oxide(MoO_(x))hole transport layer with low cost was prepared by adjusting the state of the precursor solution with an alcoholic solution of molybdenum acetylacetonate through an oxidant.The MoO_(x) transport layer has good transmittance with a work function of 5.07 eV and higher surface energy.The PM6:Y6 devices using MoO_(x) HTL achieve a high efficiency of 16.8%.MoO_(x) HTL exhibits good applicability with excellent performance in both ternary and all-polymer systems.Air storage stability T80 of the all-polymer device using MoO_(x) HTL was over 600 h,much higher than 70 h of the PEDOT:PSS-based device,and its thermal stability at 85℃ and operational stability under light show better stability than that of the PEDOT:PSS hole transport layer.This work provides a facile and low-cost method to fabricate HTL for organic solar cells,which is beneficial to improve their efficiency and stability.展开更多
Based on its band alignment,p-type nickel oxide(NiO_(x))is an excellent candidate material for hole transport layers in crystalline silicon heterojunction solar cells,as it has a smallΔEV and largeΔEC with crystalli...Based on its band alignment,p-type nickel oxide(NiO_(x))is an excellent candidate material for hole transport layers in crystalline silicon heterojunction solar cells,as it has a smallΔEV and largeΔEC with crystalline silicon.Herein,to overcome the poor hole selectivity of stoichiometric NiO_(x) due to its low carrier concentration and conductivity,silver-doped nickel oxide(NiO_(x):Ag)hole transport layers with high carrier concentrations were prepared by co-sputtering high-purity silver sheets and pure NiO_(x) targets.The improved electrical conductivity of NiO_(x) was attributed to the holes generated by the Ag^(+)substituents for Ni^(2+),and moreover,the introduction of Ag^(+)also increased the amount of Ni^(3+)present,both of which increased the carrier concentration in NiO_(x).Ag^(+)doping also reduced the c-Si/NiO_(x) contact resistivity and improved the hole-selective contact with NiO_(x).Furthermore,the problems of particle clusters and interfacial defects on the surfaces of NiO_(x):Ag films were solved by UV-ozone oxidation and high-temperature annealing,which facilitated separation and transport of carriers at the c-Si/NiO_(x) interface.The constructed c-Si/NiO_(x):Ag solar cell exhibited an increase in open-circuit voltage from 490 to 596 mV and achieved a conversion efficiency of 14.4%.展开更多
The strong aggregation tendency of hole transport material poly[3-(4-carboxylbutyl)thiophene-K(P3CT-K)restricts its further application in inverted perovskite solar cells(PSCs).Here,we report an effective strategy to ...The strong aggregation tendency of hole transport material poly[3-(4-carboxylbutyl)thiophene-K(P3CT-K)restricts its further application in inverted perovskite solar cells(PSCs).Here,we report an effective strategy to address this issue and achieve the superior performance of inverted methylammonium lead triiodide(MAPbI3)PSCs,in which graphdiyne oxide(GDYO)doped P3CT-K nanocomposites are applied as the hole transport nanolayer(HTL).It is revealed that the strongπ–πstacking interaction occurs between GDYO and P3CT-K,which is proved by the blue shift of the absorption peak of P3CT-K nanolayer.The aggregation control via GDYO contributes to the property improvement of P3CT-K HTL.Moreover,the homogeneous coverage induces the growth of perovskite grain with larger size than that based on the undoped one.As a result,the optimized surface morphology,enhanced conductivity,charge extraction as well as better crystal quality,finally improve the device performance.An optimal power conversion efficiency of 19.06%is achieved,with simultaneously improved fill factor and short circuit current density.This work presents the potential of functional graphdiyne(GDY)in the development of highly efficient photovoltaic device.展开更多
The regulated crystallization of perovskite and highly repeatable preparation are decisive challenges for large-scale flexible perovskite solar cells(PSCs).Herein,we synthesize an oil-soluble poly(3,4-ethylenedioxythi...The regulated crystallization of perovskite and highly repeatable preparation are decisive challenges for large-scale flexible perovskite solar cells(PSCs).Herein,we synthesize an oil-soluble poly(3,4-ethylenedioxythiophene)(Oil-PEDOT)as a hole transport layer(HTL).The non-wetting Oil-PEDOT HTL can promote the quality of large-area flexible perovskite films because of its optimized crystallinity and printability.The Oil-PEDOT layer also delivers desirable conductivity and charge transport without a complex doping.Consequently,the flexible PSCs with Oil-PEDOT HTL achieve an efficiency of 19.51%and 16.70%based on 1.05 and 22.50 cm^(2),respectively.Moreover,these large-scale flexible PSCs demonstrate remarkable mechanical robustness,and the efficiency exhibits 93%retention after 7,000 bending cycles.These results show that the Oil-PEDOT is a potentially efficient HTL for fabricating efficient large-scale flexible PSCs.展开更多
Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 v...Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 vacancies in NiOx film by controlling deposition temperature in a hot-casting process,resulting the change of coordination structure and charge state of NiOx.Moreover,the change of the HOMO level of NiOx makes it more compatible with perovskite to decrease energy losses and enhance hole carrier injection efficiency.Besides,the defect modulation in the electronic structure of NiOx is beneficial for increasing the electrical conductivity and mobility,which are considered to achieve the balance of charge carrier transport and avoid charge accumulation at the interface between perovskite and HTL effectively.Both experimental analyses and theoretical calculations reveal the increase of nickel vacancy defects change the electronic structure of NiOx by increasing the ratio of Ni3^+/Ni2^+-and improving the p-type characteristics.Accordingly,an optimal deposition temperature at 120℃enabled a 36.24%improvement in the power conversion efficiency compared to that deposited at room temperature(25℃).Therefore,this work provides a facile method to manipulate the electronic structure of NiOx to improve the charge carrier transport and photovoltaic performance of related PSCs.展开更多
Application of two-dimensional MXene materials in photovoltaics has attracted increasing attention since the first report in 2018 due to their metallic electrical conductivity,high carrier mobility,excellent transpare...Application of two-dimensional MXene materials in photovoltaics has attracted increasing attention since the first report in 2018 due to their metallic electrical conductivity,high carrier mobility,excellent transparency,tunable work function and superior mechanical property.In this review,all developments and applications of the Ti3C2Tx MXene(here,it is noteworthy that there are still no reports on other MXenes’application in photovoltaics by far)as additive,electrode and hole/electron transport layer in solar cells are detailedly summarized,and meanwhile,the problems existing in the related studies are also discussed.In view of these problems,some suggestions are given for pushing exploration of the MXenes’application in solar cells.It is believed that this review can provide a comprehensive and deep understanding into the research status and,moreover,helps widen a new situation for the study of MXenes in photovoltaics.展开更多
Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still ...Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still largely constrained by the widebandgap perovskite solar cells which show considerable open-circuit voltage(VOC)losses.Here,we increase the VOCand PCE of wide-bandgap perovskite solar cells by changing the hole transport layer(HTL)from commonly used poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)(PTAA)to in-situ cross-linked small molecule N_(4),N_(4)′-di(naphthalen-1-yl)-N_(4),N_(4)′-bis(4-vinylphenyl)biphenyl-4,4′-diamine(VNPB).The stronger interaction and lower trap density at the VNPB/perovskite interface improve the PCE and stability of wide-bandgap perovskite solar cells.By using the cross-linked HTL for front wide-bandgap subcells,PCEs of 24.9%and 25.4%have been achieved in perovskite/perovskite and perovskite/silicon tandem solar cells,respectively.The results demonstrate that cross-linkable small molecules are promising for high-efficiency and cost-effective perovskite tandem photovoltaic devices.展开更多
Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed ho...Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed hole transport layer(HTL)on the charge carrier dynamics and recombination processes in perovskite photovoltaic devices is still largely unexplored.In particular,significant knowledge is missing on how these crucial parameters for radiative and non-radiative recombinations,as well as for efficient charge extraction vary among different perovskite crystalline phases that are induced by temperature variation.Herein,we perform micro photoluminescence(pPL)and ultrafast time resolved transient absorption spectroscopy(TAS)in Glass/Perovskite and two dierent Glass/ITO/HTL/Perovskite configurations at temperatures below room temperature,in order to probe the charge carrier dynamics of different perovskite crystalline phases,while considering also the effect of the employed HTL polymer.Namely,CH_(3)NH_(3)Pbb films were deposited on Glass,PEDOT:PSS and PTAA polymers,and the developed Glass/CH_(3)NH_(3)PbI_(3)and Glass/ITO/HTL/CH_(3)NH_(3)PbI_(3)architectures were studied from 85 K up to 215 K in order to explore the charge extraction dynamics of the CH_(3)NH_(3)PbI_(3)orthorhombic and tetragonal crystalline phases.It is observed an unusual blueshift of the bandgap with temperature and the dual emission at temperature below of 100 K and also,that the charge carrier dynamics,as expressed by hole injection times and free carrier recombination rates,are strongly depended on the actual pervoskite crystal phase,as well as,from the selected hole transport material.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
A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocki...A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocking and hole extraction properties for its suitable work function and high-conduction band edge position.Herein,the transparent and high-crystalline NiO_(x) film is prepared by thermal-decomposing of the solution-derived Ni(OH)_(2) film in our study,which is then employed as hole transport layer(HTL)of the organic–inorganic hybrid PSCs.Reasonably,the post-annealing treatment,especially for the annealing temperature,could greatly affect the Ni(OH)_(2) decomposition process and the quality of decomposed NiO_(x) nanoparticles.The vital NiO_(x) HTLs with discrepant morphology,crystallinity and transmission certainly lead to a wide range of device performance.As a result,an annealing process of 400℃/2 h significantly promotes the photovoltaic properties of the NiO_(x) layer and the further device performance.展开更多
基金supported by the National Natural Science Foundation of China (21975028, U21A20172 and 22011540377)the Special Key Projects (2022-JCJQ-ZD-224-12)。
文摘To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB1500103)the National Natural Science Foundation of China(Grant No.61674084)+1 种基金the Overseas Expertise Introduction Project for Discipline Innovation of Higher Education of China(Grant No.B16027)the Science and Technology Project of Tianjin,China(Grant No.18ZXJMTG00220).
文摘Coper thiocyanate(CuSCN)is generally considered as a very hopeful inorganic hole transport material(HTM)in semitransparent perovskite solar cells(ST-PSCs)because of its low parasitic absorption,high inherent stability,and low cost.However,the poor electrical conductivity and low work function of CuSCN lead to the insufficient hole extraction and large open-circuit voltage loss.Here,2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4TCNQ)is employed to improve conductivity of CuSCN and band alignment at the CuSCN/perovskite(PVK)interface.As a result,the average power conversion efficiency(PCE)of PSCs is boosted by≈11%.In addition,benefiting from the superior transparency of p-type CuSCN HTMs,the prepared bifacial semitransparent n-i-p planar PSCs demonstrate a maximum efficiency of 14.8%and 12.5%by the illumination from the front side and back side,respectively.We believe that this developed CuSCN-based ST-PSCs will promote practical applications in building integrated photovoltaics and tandem solar cells.
基金supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2021QN1110)。
文摘Perovskite solar cells(PSCs) are the most promising commercial photoelectric conversion technology in the future.The planar p–i–n structure cells have advantages in negligible hysteresis, low temperature preparation and excellent stability.However, for inverted planar PSCs, the non-radiative recombination at the interface is an important reason that impedes the charge transfer and improvement of power conversion efficiency. Having a homogeneous, compact, and energy-levelmatched charge transport layer is the key to reducing non-radiative recombination. In our study, NiO_(x)/Sr:NiO_(x)bilayer hole transport layer(HTL) improves the holes transmission of NiO_(x)based HTL, reduces the recombination in the interface between perovskite and HTL layer and improves the device performance. The bilayer HTL enhances the hole transfer by forming a driving force of an electric field and further improves J_(sc). As a result, the device has a power conversion efficiency of 18.44%, a short circuit current density of 22.81 m A·cm^(-2) and a fill factor of 0.80. Compared to the pristine PSCs, there are certain improvements of optical parameters. This method provides a new idea for the future design of novel hole transport layers and the development of high-performance solar cells.
基金Supported by the National Natural Science Foundation of China under Grant No 11274402the National Basic Research Program of China under Grant No 2012CB933704+1 种基金the Natural Science Foundation of Guangdong Province under Grant No S2012020011003the Program for Changjiang Scholars and Innovative Research Team in University under Grant No IRT13042
文摘We improve the performance of organic light-emitting diodes (OLEDs) with both a MoO3 hole injection layer (HIL) and a MoO3 doped hole transport layer (HTL), and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.
基金Project supported by the National Key Basic Research and Development Program of China(Grant No.2010CB327701)the National Natural Science Foundation of China(Grant No.61275033)
文摘We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine (ZnPc)-based composite hole transport layer (c-HTL). The optimum ris-(8-hydroxyquinoline)aluminum (Alq3)-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device (turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W). We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis(1-naphthyl)(1,1’-biphenyl)-4,4’diamine (NPB):ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.
基金supported by the National Natural Science Foundation of China(Nos.22179042 and U21A2078)the Natural Science Foundation of Fujian Province(Nos.2020J06021 and 2020J01064).
文摘Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is unstable at elevated temperatures and high humidity.In this work,aπ-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)](PBDB-T)is selected to form a polymer composite hole transport layer(HTL)with Spiro-OMeTAD.The sulfur atom of the thiophene unit and the carbonyl group of the polymer interact with the undercoordinated Pb2+at the perovskite surface,which stabilizes the perovskite/HTL interface and passivates the interfacial defects.The incorporation of the polymer also increases the glass transition temperature and the moisture resistance of Spiro-OMeTAD.As a result,we obtain ST-PSCs with a champion efficiency of 13.71%and an average visible light transmittance of 36.04%.Therefore,a high light utilization efficiency of 4.94%can be obtained.Moreover,the encapsulated device can maintain 84%of the initial efficiency after 751 h under continuous one-sun illumination(at 30%relative humidity)at the open circuit and the unencapsulated device can maintain 80%of the initial efficiency after maximum power tracking for more than 1250 h under continuous one-sun illumination.
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This work was supported by Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2019B007)the Heilongjiang Provincial Postdoctoral Science Foundation(Grant No.LBH-TZ0604)the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology(Grant No.HIT.NSRIF2019042).
文摘In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The power conversion efficiency has rapidly increased by more than 6 times to the current 25.5% in the past decade. Hole transport materials (HTMs) are an indispensable part of PSCs, which great affect the efficiency, the cost and the stability of PSCs. Inorganic Cu-based p-type semiconductors are a kind of representative inorganic HTMs in PSCs due to their unique advantages of rich variety, low cost, excellent hole mobility, adjustable energy levels, good stability, low temperature and scalable processing ability. In this review, the research progress in new materials and the control of photoelectric properties of Cu-based inorganic HTMs were first summarized systematically. And then, concerning different processing methods, advances of the interface engineering of Cu-based hole transport layers (HTLs) in PSCs were detailly discussed. Finally, the challenges and future trends of Cu-based inorganic HTMs and their interface engineering in PSCs were analyzed.
基金Project supported by the National Natural Science Foundation of China(Grant No.62074084)the National Key Research and Development Program of China(Grant No.2018YFB1500402)Key Research and Development Program of Hebei Province,China(Grant No.20314303D).
文摘The silicon heterojunction(SHJ)solar cell has long been considered as one of the most promising candidates for the next-generation PV market.Transition metal oxides(TMOs)show good carrier selectivity when combined with c-Si solar cells.This has led to the rapid demonstration of the remarkable potential of TMOs(especially MoO_(x))with high work function to replace the p-type a-Si:H emitting layer.MoO_(x) can induce a strong inversion layer on the interface of n-type c-Si,which is beneficial to the extraction and conduction of holes.In this paper,the radio-frequency(RF)magnetron sputtering is used to deposit MoO_(x) films.The optical,electrical and structural properties of MoO_(x) films are measured and analyzed,with focus on the inherent compositions and work function.Then the MoO_(x) films are applied into SHJ solar cells.When the MoO_(x) works as a buffer layer between ITO/p-a-Si:H interface in the reference SHJ solar cell,a conversion efficiency of 19.1%can be obtained.When the MoOx is used as a hole transport layer(HTL),the device indicates a desirable conversion efficiency of 17.5%.To the best of our knowledge,this current efficiency is the highest one for the MoO_(x) film as HTL by RF sputtering.
基金supported by the Shenzhen Overseas High-level Talents Innovation Plan of Technical Innovation(Grant No.KQJSCX20180323140712012)the Major Program of Guangdong Basic and Applied Research(Grant No.2019B121205001)。
文摘This report presents two non-perihperally octaalkyl-substituted nickel phthalocyanines(NiPcs),namely,NiEt2Pc and NiPr_(2)Pc,for use as dopant-free hole transport materials in perovskite solar cells(PSCs).The length extension of the alkyl chains from ethyl to propyl significantly tunes the NiPcs’energy levels,thus reducing charge carrier recombination at the perovskite/hole transport layer(HTL)interface and leading to higher open-circuit voltage(VOC)and short-circuit current density(JSC)observed for the NiPr_(2)Pc-based PSC.And higher charge carrier mobility,higher thin film crystallinity,and lower surface roughness of the NiPr_(2)Pc HTL compared with that of the NiEt2Pc one also lead to higher JSC and fill factor(FF)observed for the NiPr_(2)Pc-based device.Consequently,the NiPr_(2)Pc-based PSC exhibits a higher power conversion efficiency(PCE)of 14.07%than that of the NiEt2Pc-based device(8.63%).
基金the National Natural Science Foundation of China(No.21922505)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000).
文摘The hole transport layer(HTL)affects the device performance and stability of organic solar cells.In this work,a stable molybdenum oxide(MoO_(x))hole transport layer with low cost was prepared by adjusting the state of the precursor solution with an alcoholic solution of molybdenum acetylacetonate through an oxidant.The MoO_(x) transport layer has good transmittance with a work function of 5.07 eV and higher surface energy.The PM6:Y6 devices using MoO_(x) HTL achieve a high efficiency of 16.8%.MoO_(x) HTL exhibits good applicability with excellent performance in both ternary and all-polymer systems.Air storage stability T80 of the all-polymer device using MoO_(x) HTL was over 600 h,much higher than 70 h of the PEDOT:PSS-based device,and its thermal stability at 85℃ and operational stability under light show better stability than that of the PEDOT:PSS hole transport layer.This work provides a facile and low-cost method to fabricate HTL for organic solar cells,which is beneficial to improve their efficiency and stability.
基金supported by the National Natural Science Foundation of China(Grant No.61974076)the China National Key R&D Program(Grant No.2022YFC2807104).
文摘Based on its band alignment,p-type nickel oxide(NiO_(x))is an excellent candidate material for hole transport layers in crystalline silicon heterojunction solar cells,as it has a smallΔEV and largeΔEC with crystalline silicon.Herein,to overcome the poor hole selectivity of stoichiometric NiO_(x) due to its low carrier concentration and conductivity,silver-doped nickel oxide(NiO_(x):Ag)hole transport layers with high carrier concentrations were prepared by co-sputtering high-purity silver sheets and pure NiO_(x) targets.The improved electrical conductivity of NiO_(x) was attributed to the holes generated by the Ag^(+)substituents for Ni^(2+),and moreover,the introduction of Ag^(+)also increased the amount of Ni^(3+)present,both of which increased the carrier concentration in NiO_(x).Ag^(+)doping also reduced the c-Si/NiO_(x) contact resistivity and improved the hole-selective contact with NiO_(x).Furthermore,the problems of particle clusters and interfacial defects on the surfaces of NiO_(x):Ag films were solved by UV-ozone oxidation and high-temperature annealing,which facilitated separation and transport of carriers at the c-Si/NiO_(x) interface.The constructed c-Si/NiO_(x):Ag solar cell exhibited an increase in open-circuit voltage from 490 to 596 mV and achieved a conversion efficiency of 14.4%.
基金supported by the National Natural Science Foundation of China(No.21975273)Scientific Research Starting Foundation of Outstanding Young Scholar of Shandong University,and the Fundamental Research Funds of Shandong University+2 种基金We thank Guangdong Basic and Applied Basic Research Foundation(No.2019A1515012156)2020 Li Ka Shing Foundation Cross Disciplinary Research Grant(No.2020LKSFG01A)Department of Education of Guangdong Province(Nos.2021LSYS009 and 2021KCXTD032).
文摘The strong aggregation tendency of hole transport material poly[3-(4-carboxylbutyl)thiophene-K(P3CT-K)restricts its further application in inverted perovskite solar cells(PSCs).Here,we report an effective strategy to address this issue and achieve the superior performance of inverted methylammonium lead triiodide(MAPbI3)PSCs,in which graphdiyne oxide(GDYO)doped P3CT-K nanocomposites are applied as the hole transport nanolayer(HTL).It is revealed that the strongπ–πstacking interaction occurs between GDYO and P3CT-K,which is proved by the blue shift of the absorption peak of P3CT-K nanolayer.The aggregation control via GDYO contributes to the property improvement of P3CT-K HTL.Moreover,the homogeneous coverage induces the growth of perovskite grain with larger size than that based on the undoped one.As a result,the optimized surface morphology,enhanced conductivity,charge extraction as well as better crystal quality,finally improve the device performance.An optimal power conversion efficiency of 19.06%is achieved,with simultaneously improved fill factor and short circuit current density.This work presents the potential of functional graphdiyne(GDY)in the development of highly efficient photovoltaic device.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(5167,3091,22005131,U20A20128,51833004)the National Science Fund for Distinguished Young Scholars(51425304)NSFC-Guangdong Joint funding,China(U1801256).
文摘The regulated crystallization of perovskite and highly repeatable preparation are decisive challenges for large-scale flexible perovskite solar cells(PSCs).Herein,we synthesize an oil-soluble poly(3,4-ethylenedioxythiophene)(Oil-PEDOT)as a hole transport layer(HTL).The non-wetting Oil-PEDOT HTL can promote the quality of large-area flexible perovskite films because of its optimized crystallinity and printability.The Oil-PEDOT layer also delivers desirable conductivity and charge transport without a complex doping.Consequently,the flexible PSCs with Oil-PEDOT HTL achieve an efficiency of 19.51%and 16.70%based on 1.05 and 22.50 cm^(2),respectively.Moreover,these large-scale flexible PSCs demonstrate remarkable mechanical robustness,and the efficiency exhibits 93%retention after 7,000 bending cycles.These results show that the Oil-PEDOT is a potentially efficient HTL for fabricating efficient large-scale flexible PSCs.
基金financially supported by the National Natural Science Foundation of China NSFC(51702038)the Recruitment Program for Young Professionals+1 种基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)for financial support。
文摘Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 vacancies in NiOx film by controlling deposition temperature in a hot-casting process,resulting the change of coordination structure and charge state of NiOx.Moreover,the change of the HOMO level of NiOx makes it more compatible with perovskite to decrease energy losses and enhance hole carrier injection efficiency.Besides,the defect modulation in the electronic structure of NiOx is beneficial for increasing the electrical conductivity and mobility,which are considered to achieve the balance of charge carrier transport and avoid charge accumulation at the interface between perovskite and HTL effectively.Both experimental analyses and theoretical calculations reveal the increase of nickel vacancy defects change the electronic structure of NiOx by increasing the ratio of Ni3^+/Ni2^+-and improving the p-type characteristics.Accordingly,an optimal deposition temperature at 120℃enabled a 36.24%improvement in the power conversion efficiency compared to that deposited at room temperature(25℃).Therefore,this work provides a facile method to manipulate the electronic structure of NiOx to improve the charge carrier transport and photovoltaic performance of related PSCs.
基金This work was financially supported from the National Natural Science Foundation of China(Grant Nos.:61376068,11304132,11304133 and 61804070)the Fundamental Research Funds for the Central Universities(Grant Nos.:lzujbky-2016-112,lzujbky-2017-178 and lzujbky-2017-181).
文摘Application of two-dimensional MXene materials in photovoltaics has attracted increasing attention since the first report in 2018 due to their metallic electrical conductivity,high carrier mobility,excellent transparency,tunable work function and superior mechanical property.In this review,all developments and applications of the Ti3C2Tx MXene(here,it is noteworthy that there are still no reports on other MXenes’application in photovoltaics by far)as additive,electrode and hole/electron transport layer in solar cells are detailedly summarized,and meanwhile,the problems existing in the related studies are also discussed.In view of these problems,some suggestions are given for pushing exploration of the MXenes’application in solar cells.It is believed that this review can provide a comprehensive and deep understanding into the research status and,moreover,helps widen a new situation for the study of MXenes in photovoltaics.
基金financially supported by the National Key R&D Program of China(2018YFB1500102)the National Natural Science Foundation of China(61974063,22005139)+5 种基金Natural Science Foundation of Jiangsu Province(BK20202008,BK20190315)Fundamental Research Funds for the Central Universities(0205/14380252)Program for Innovative Talents and Entrepreneur in Jiangsusupported by the National Natural Science Foundation of China(62074153)Strategic Priority Research Program of Chinese Academy of Sciences(XDA17020403)Science and Technology Commission of Shanghai(19DZ1207602 and 20DZ1207103)。
文摘Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still largely constrained by the widebandgap perovskite solar cells which show considerable open-circuit voltage(VOC)losses.Here,we increase the VOCand PCE of wide-bandgap perovskite solar cells by changing the hole transport layer(HTL)from commonly used poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)(PTAA)to in-situ cross-linked small molecule N_(4),N_(4)′-di(naphthalen-1-yl)-N_(4),N_(4)′-bis(4-vinylphenyl)biphenyl-4,4′-diamine(VNPB).The stronger interaction and lower trap density at the VNPB/perovskite interface improve the PCE and stability of wide-bandgap perovskite solar cells.By using the cross-linked HTL for front wide-bandgap subcells,PCEs of 24.9%and 25.4%have been achieved in perovskite/perovskite and perovskite/silicon tandem solar cells,respectively.The results demonstrate that cross-linkable small molecules are promising for high-efficiency and cost-effective perovskite tandem photovoltaic devices.
文摘Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed hole transport layer(HTL)on the charge carrier dynamics and recombination processes in perovskite photovoltaic devices is still largely unexplored.In particular,significant knowledge is missing on how these crucial parameters for radiative and non-radiative recombinations,as well as for efficient charge extraction vary among different perovskite crystalline phases that are induced by temperature variation.Herein,we perform micro photoluminescence(pPL)and ultrafast time resolved transient absorption spectroscopy(TAS)in Glass/Perovskite and two dierent Glass/ITO/HTL/Perovskite configurations at temperatures below room temperature,in order to probe the charge carrier dynamics of different perovskite crystalline phases,while considering also the effect of the employed HTL polymer.Namely,CH_(3)NH_(3)Pbb films were deposited on Glass,PEDOT:PSS and PTAA polymers,and the developed Glass/CH_(3)NH_(3)PbI_(3)and Glass/ITO/HTL/CH_(3)NH_(3)PbI_(3)architectures were studied from 85 K up to 215 K in order to explore the charge extraction dynamics of the CH_(3)NH_(3)PbI_(3)orthorhombic and tetragonal crystalline phases.It is observed an unusual blueshift of the bandgap with temperature and the dual emission at temperature below of 100 K and also,that the charge carrier dynamics,as expressed by hole injection times and free carrier recombination rates,are strongly depended on the actual pervoskite crystal phase,as well as,from the selected hole transport material.
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.
基金funded by the National Natural Science Foundation of China(51502239)China Postdoctoral Science Foundation(2017T100751)+1 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2016JQ6058)Postdoctoral Science Foundation in Shaanxi Province of China and the 111 Project of China(B14040)。
文摘A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocking and hole extraction properties for its suitable work function and high-conduction band edge position.Herein,the transparent and high-crystalline NiO_(x) film is prepared by thermal-decomposing of the solution-derived Ni(OH)_(2) film in our study,which is then employed as hole transport layer(HTL)of the organic–inorganic hybrid PSCs.Reasonably,the post-annealing treatment,especially for the annealing temperature,could greatly affect the Ni(OH)_(2) decomposition process and the quality of decomposed NiO_(x) nanoparticles.The vital NiO_(x) HTLs with discrepant morphology,crystallinity and transmission certainly lead to a wide range of device performance.As a result,an annealing process of 400℃/2 h significantly promotes the photovoltaic properties of the NiO_(x) layer and the further device performance.