CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improv...CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.展开更多
All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading ...All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.展开更多
All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite sol...All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite solar cells(PSCs)was limited by severe nonradiative charge recombination due to high defect density at the grain boundary and surface of perovskitefilms.To address this issue,a pyrrolidinium iodide(PyI)molecule was introduced to modify the surface and grain boundary of CsPbI_(3) perovskitefilms to passivate defects,which improves the quality of CsPbI_(3) perovskitefilms as well as induces the generation of a quasi-2D Py_(2)CsPb_(2)I_(7) capping layer between per-ovskite layer and hole transport layer.Such quasi-2D Py_(2)CsPb_(2)I_(7) capping layer optimizes interface contact between CsPbI_(3) perovskite layer and hole transport layer and blocks the electron transfer from CsPbI_(3) perovskite photoactive layer to the hole transport layer.As a result,the performance of CsPbI_(3) PSCs is well improved to 17.87%for power conversion efficiency(PCE)with an ultra-high fill factor(FF)of 0.84.In addition,the PyI mole-cule modified CsPbI_(3) perovskite devices exhibit excellent stability,which remains its initial PCE almost unchanged after aging for 35 days under the dry air atmosphere(temperature:20℃–30℃,control relative humid-ity(RH):<10%).展开更多
The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material.In particular,nanocrystals(NCs)of inorganic perovskites have demonstrated excellen...The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material.In particular,nanocrystals(NCs)of inorganic perovskites have demonstrated excellent performance for light-emitting and display applications.However,the presence of surface defects on the NCs negatively impacts their performance in devices.Herein,we report a compatible facial post-treatment of CsPbI_(3) nanocrystals using guanidinium iodide(GuI).It is found that the GuI treatment effectively passivated the halide vacancy defects on the surface of the NCs while offering effective surface protection and exciton confinement thanks to the beneficial contribution of iodide and guanidinium cation.As a consequence,the film of treated CsPbI_(3) nanocrystals exhibited significantly enhanced luminescence and charge transport properties,leading to high-performance light-emitting diode with maximum external quantum efficiency of 13.8%with high brightness(peak luminance of 7039 cd m^(−2) and a peak current density of 10.8 cd A^(−1)).The EQE is over threefold higher than performance of untreated device(EQE:3.8%).The operational half-lifetime of the treated devices also was significantly improved with T50 of 20 min(at current density of 25 mA cm^(−2)),outperforming the untreated devices(T50~6 min).展开更多
In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain bo...In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain boundaries, severely limit the stabilization and efficiency of solar cells. In this work, we adopt 3-carboxyphenylboronic acid(CPBA) for modifying defects in perovskite thin films. Through the interaction among the carboxyl group, boronic acid and lead ions in the perovskite film, the crystallization effect of the perovskite molecular is greatly optimized. Moreover, the film defects are spontaneously passivated and the band gap is reduced, increasing the open circuit voltage and fill factor. Therefore,power conversion efficiency has been increased from 17.25% to 20.20%. This discovery provides a potential strategy for passivating the trap states in perovskite and enhancing the properties of devices.展开更多
Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by gra...Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by grain boundaries,which seriously hinder the further improvement of power conversion efficiency and stability.Herein,a novel carbon nitride C_(3)N_(3) incorporated into the perovskite precursor solution is a multifunctional strategy,which not only increases the light absorption strength,grain size,and hydrophobicity of the perovskite film,but also effectively passivates the bulk and interfacial defects of perovskite and verified by the first-principles density functional theory calculations.As a result,the efficiency and stability of perovskite solar cells are improved.The device with 0.075 mg mL^(-1) C_(3)N_(3) additive delivers a champion power conversion efficiency of 19.91%with suppressed hysteresis,which is significantly higher than the 18.16% of the control device.In addition,the open-circuit voltage of the modified device with the maximum addition as high as 1.137 V is 90.96% of the Shockley–Queisser limit(1.25 V).Moreover,the power conversion efficiency of the modified device without encapsulation can maintain nearly 90% of its initial value after being stored at 25℃ and 60% relative humidity for 500 h.This work provides a new idea for developing additives to improve the power conversion efficiency and stability of perovskite solar cells.展开更多
The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are...The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.展开更多
CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state d...CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.展开更多
Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harve...Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harvesting applications. However, compared to solar cells fabricated from organic-inorganic hybrid perovskites, the commercialization of devices based on all-inorganic CsPbI_(3) perovskites still faces many challenges regarding PV performance and long-term stability. In this work, we discovered that tetrabutylammonium bromide(TBABr) post-treatment to CsPbI_(3) perovskite films could achieve synergistic stabilization with both TBA+cation intercalation and Br-doping. Such TBA^(+) cation intercalation leads to onedimensional capping with TBAPb I3 perovskite formed in situ, while the Br-induced crystal secondary growth helps effectively passivate the defects of CsPbI_(3) perovskite, thus enhancing the stability. In addition, the incorporation of TBABr can improve energy-level alignment and reduce interfacial charge recombination loss for better device performance. Finally, the highly stable TBABr-treated CsPbI_(3)-based perovskite solar cells show reproducible photovoltaic performance with a champion efficiency up to 19.04%, while retaining 90% of the initial efficiency after 500 h storage without encapsulation.展开更多
In the construction of high performance planar perovskite solar cells(PSCs),the modification of compact TiO_(2) layer and engineering of perovskite/TiO_(2) interfaces are essential for efficient electron transfer and ...In the construction of high performance planar perovskite solar cells(PSCs),the modification of compact TiO_(2) layer and engineering of perovskite/TiO_(2) interfaces are essential for efficient electron transfer and retarded charge recombination loss.In this work,a facile and effective strategy is developed to modify the surface of compact TiO_(2) layer by TiCl_(4)-TiCl_(3) mixture treatment.Compared with conventional sole TiCl_(4),the TiCl_(4)-TiCl_(3) treatment takes the advantage of accelerated and controlled hydrolysis of TiCl_(3),therefore TiO_(2) with dominating anatase phase and moderate roughness is obtained to facilitate the growth of CsPbI_(2) Br perovskite layer with high quality.Furthermore,the oxidation-driven hydrolysis of TiCl_(3) component results in surface Cl doping that facilitates interfacial electron transfer with retarded recombination loss.The average power conversion efficiency(PCE) of carbon-based CsPbI_(2) Br planar PSCs based on TiCl_(4)-TiCl_(3) treatment increases to 14.18% from the intial 13.04% based on conventional sole TiCl_(4) treatment.The champion PSC exhibits a PCE of 14.46%(V_(oc)=1.28 V,J_(sc)=14.21 mA/cm^(2),and FF=0.794),which is one of the highest PCEs for carbon-based CsPbI_(2) Br PSCs.展开更多
High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unpa...High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unparalleled performance,the relationships between multiple active sites and reaction intermediates are still obscure.Here,enlightened by theoretical screening,we tailor a high-entropy perovskite fluoride(KCoMnNiMgZnF_(3)-HEC)with various active sites to overcome the limitations of conventional catalysts in redox process.The entropy effect modulates the d-band center and d orbital occupancy of active centers,which optimizes the d–p hybridization between catalytic sites and key intermediates,enabling a moderate adsorption of LiO_(2)and thus reinforcing the reaction kinetics.As a result,the Li–O2 battery with KCoMnNiMgZnF_(3)-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability,preceding majority of traditional catalysts reported.These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(2022YFB3602902)the Key Projects of National Natural Science Foundation of China(62234004)+5 种基金Innovation and Entrepreneurship Team of Zhejiang Province(2021R01003)Science and Technology Innovation 2025 Major Project of Ningbo(2022Z085)Ningbo 3315 Programme(2020A-01-B)YONGJIANG Talent Introduction Programme(2021A-038-B)Flexible Electronics Zhejiang Province Key Laboratory Fund Project(2022FEO02)Zhejiang Provincial Natural Science Foundation of China(LR21F050001).
文摘CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB3800101 and 2022YFE0110300)National Natural Science Foundation of China (No. U19A2089, 52261145696, 52073198, 92163114, and 22161142003)+3 种基金Natural Science Foundation of Jiangsu Province (BK20211598)“111” projectthe Young Elite Scientist Sponsorship Program by CASTCollaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University。
文摘All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.
基金National Natural Science Foundation of China,Grant No.21875013,H.N.ChenBeijing Natural Science Foundation,Grant No.2182031,H.N.Chen.
文摘All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite solar cells(PSCs)was limited by severe nonradiative charge recombination due to high defect density at the grain boundary and surface of perovskitefilms.To address this issue,a pyrrolidinium iodide(PyI)molecule was introduced to modify the surface and grain boundary of CsPbI_(3) perovskitefilms to passivate defects,which improves the quality of CsPbI_(3) perovskitefilms as well as induces the generation of a quasi-2D Py_(2)CsPb_(2)I_(7) capping layer between per-ovskite layer and hole transport layer.Such quasi-2D Py_(2)CsPb_(2)I_(7) capping layer optimizes interface contact between CsPbI_(3) perovskite layer and hole transport layer and blocks the electron transfer from CsPbI_(3) perovskite photoactive layer to the hole transport layer.As a result,the performance of CsPbI_(3) PSCs is well improved to 17.87%for power conversion efficiency(PCE)with an ultra-high fill factor(FF)of 0.84.In addition,the PyI mole-cule modified CsPbI_(3) perovskite devices exhibit excellent stability,which remains its initial PCE almost unchanged after aging for 35 days under the dry air atmosphere(temperature:20℃–30℃,control relative humid-ity(RH):<10%).
基金supported by Australian Research Council Discovery Project(DP190102252).
文摘The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material.In particular,nanocrystals(NCs)of inorganic perovskites have demonstrated excellent performance for light-emitting and display applications.However,the presence of surface defects on the NCs negatively impacts their performance in devices.Herein,we report a compatible facial post-treatment of CsPbI_(3) nanocrystals using guanidinium iodide(GuI).It is found that the GuI treatment effectively passivated the halide vacancy defects on the surface of the NCs while offering effective surface protection and exciton confinement thanks to the beneficial contribution of iodide and guanidinium cation.As a consequence,the film of treated CsPbI_(3) nanocrystals exhibited significantly enhanced luminescence and charge transport properties,leading to high-performance light-emitting diode with maximum external quantum efficiency of 13.8%with high brightness(peak luminance of 7039 cd m^(−2) and a peak current density of 10.8 cd A^(−1)).The EQE is over threefold higher than performance of untreated device(EQE:3.8%).The operational half-lifetime of the treated devices also was significantly improved with T50 of 20 min(at current density of 25 mA cm^(−2)),outperforming the untreated devices(T50~6 min).
基金Project supported by the Regional Joint Fund of the National Science Foundation of China (Grant No. U21A20492)the Sichuan Science and Technology Program (Grant Nos. 2022YFH0081, 2022YFG0012, and 2022YFG0013)+1 种基金sponsored by the Sichuan Province Key Laboratory of Display Science and TechnologyQiantang Science & Technology Innovation Center。
文摘In the past period of time, perovskite solar cells have gained tremendous developments in improving photovoltaic performance, but they still face severe challenges. Defects in perovskite layers, especially at grain boundaries, severely limit the stabilization and efficiency of solar cells. In this work, we adopt 3-carboxyphenylboronic acid(CPBA) for modifying defects in perovskite thin films. Through the interaction among the carboxyl group, boronic acid and lead ions in the perovskite film, the crystallization effect of the perovskite molecular is greatly optimized. Moreover, the film defects are spontaneously passivated and the band gap is reduced, increasing the open circuit voltage and fill factor. Therefore,power conversion efficiency has been increased from 17.25% to 20.20%. This discovery provides a potential strategy for passivating the trap states in perovskite and enhancing the properties of devices.
基金This work was financially supported by National Natural Science Foundation of China(52002121,62004064,21873027,and 21905219)the Key Program for Inter-governmental S&T Innovation Cooperation Projects of National Key R&D Pro-gram of China(2019YFE0107100)+1 种基金Natural Science Foundation of Hubei Province(2020CFA091)Overseas Expertise Introduction Center for Discipline Innova-tion(D18025).
文摘Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by grain boundaries,which seriously hinder the further improvement of power conversion efficiency and stability.Herein,a novel carbon nitride C_(3)N_(3) incorporated into the perovskite precursor solution is a multifunctional strategy,which not only increases the light absorption strength,grain size,and hydrophobicity of the perovskite film,but also effectively passivates the bulk and interfacial defects of perovskite and verified by the first-principles density functional theory calculations.As a result,the efficiency and stability of perovskite solar cells are improved.The device with 0.075 mg mL^(-1) C_(3)N_(3) additive delivers a champion power conversion efficiency of 19.91%with suppressed hysteresis,which is significantly higher than the 18.16% of the control device.In addition,the open-circuit voltage of the modified device with the maximum addition as high as 1.137 V is 90.96% of the Shockley–Queisser limit(1.25 V).Moreover,the power conversion efficiency of the modified device without encapsulation can maintain nearly 90% of its initial value after being stored at 25℃ and 60% relative humidity for 500 h.This work provides a new idea for developing additives to improve the power conversion efficiency and stability of perovskite solar cells.
文摘The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.
基金financially supported by the Guangzhou Basic and Applied Basic Research Foundation,China(No.303523)。
文摘CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.
基金support from the National Natural Science Foundation of China (Grant Nos. 22025505, 51861145101,21777096)the Program of Shanghai Academic/Technology Research Leader (Grant No. 20XD1422200)+1 种基金the Key Laboratory of Resource Chemistry,Ministry of Education (Grant No.KLRC_ME2003)support from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University。
文摘Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harvesting applications. However, compared to solar cells fabricated from organic-inorganic hybrid perovskites, the commercialization of devices based on all-inorganic CsPbI_(3) perovskites still faces many challenges regarding PV performance and long-term stability. In this work, we discovered that tetrabutylammonium bromide(TBABr) post-treatment to CsPbI_(3) perovskite films could achieve synergistic stabilization with both TBA+cation intercalation and Br-doping. Such TBA^(+) cation intercalation leads to onedimensional capping with TBAPb I3 perovskite formed in situ, while the Br-induced crystal secondary growth helps effectively passivate the defects of CsPbI_(3) perovskite, thus enhancing the stability. In addition, the incorporation of TBABr can improve energy-level alignment and reduce interfacial charge recombination loss for better device performance. Finally, the highly stable TBABr-treated CsPbI_(3)-based perovskite solar cells show reproducible photovoltaic performance with a champion efficiency up to 19.04%, while retaining 90% of the initial efficiency after 500 h storage without encapsulation.
基金supported by the National Natural Science Foundation of China (51732004, 21805093, 21975083, 2170307122075090)the Science and Technology Program of Guangzhou,China (201904010178)。
文摘In the construction of high performance planar perovskite solar cells(PSCs),the modification of compact TiO_(2) layer and engineering of perovskite/TiO_(2) interfaces are essential for efficient electron transfer and retarded charge recombination loss.In this work,a facile and effective strategy is developed to modify the surface of compact TiO_(2) layer by TiCl_(4)-TiCl_(3) mixture treatment.Compared with conventional sole TiCl_(4),the TiCl_(4)-TiCl_(3) treatment takes the advantage of accelerated and controlled hydrolysis of TiCl_(3),therefore TiO_(2) with dominating anatase phase and moderate roughness is obtained to facilitate the growth of CsPbI_(2) Br perovskite layer with high quality.Furthermore,the oxidation-driven hydrolysis of TiCl_(3) component results in surface Cl doping that facilitates interfacial electron transfer with retarded recombination loss.The average power conversion efficiency(PCE) of carbon-based CsPbI_(2) Br planar PSCs based on TiCl_(4)-TiCl_(3) treatment increases to 14.18% from the intial 13.04% based on conventional sole TiCl_(4) treatment.The champion PSC exhibits a PCE of 14.46%(V_(oc)=1.28 V,J_(sc)=14.21 mA/cm^(2),and FF=0.794),which is one of the highest PCEs for carbon-based CsPbI_(2) Br PSCs.
基金P.G.acknowledges the financial support from the Youth Foundation of Shandong Natural Science Foundation(No.ZR2023OB230)National Natural Science Foundation(No.22309035)Double First-class Discipline Construction Fund Project of Harbin Institute of Technology at Weihai(No.2023SYLHY11).
文摘High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unparalleled performance,the relationships between multiple active sites and reaction intermediates are still obscure.Here,enlightened by theoretical screening,we tailor a high-entropy perovskite fluoride(KCoMnNiMgZnF_(3)-HEC)with various active sites to overcome the limitations of conventional catalysts in redox process.The entropy effect modulates the d-band center and d orbital occupancy of active centers,which optimizes the d–p hybridization between catalytic sites and key intermediates,enabling a moderate adsorption of LiO_(2)and thus reinforcing the reaction kinetics.As a result,the Li–O2 battery with KCoMnNiMgZnF_(3)-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability,preceding majority of traditional catalysts reported.These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.
