Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite...Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite-based self-powered photodetectors containing inorganic copper thiocyanate(CuSCN) as hole-transport layers(HTLs) are successfully fabricated and applied for weak light imaging,which is the first report on the weak light imaging application of all-inorganic lead-free perovskite photodetectors. CuSCN films with favorable optical property and hole extraction capability are prepared via a cost efficient and fast solvent removal method, demonstrating the potential for high-performance perovskite-based devices as transparent components. It is revealed that the band alignment of the device is effectively optimized with the presence of CuSCN HTLs,which can availably transport holes while block electrons at the Cs2AgBiBr6/CuSCN interface, resulting in remarkable improvement of photoresponse performance. The responsivity and detectivity are 0.34 A W^-1 and 1.03×10^13 Jones,respectively. In particular, the light current has a boost of almost 10 times. Furthermore, the photodetectors are integrated into a self-built light detection imaging system utilizing the focused laser scanning imaging mode. With illumination of as low as 5 nW cm^-2(405 nm), the image involving graphics and words with a size of 5 cm×5 cm can still be distinctly recognized. These results suggest the promising potential of all-inorganic perovskite-based devices for weak light detection and imaging applications.展开更多
Solution-processed cadmium-based quantum dots(QDs)light-emitting diodes(QLEDs)have shown promising for high-definition display panels due to their high colour purity and low-cost fabrication,but the toxicity still is ...Solution-processed cadmium-based quantum dots(QDs)light-emitting diodes(QLEDs)have shown promising for high-definition display panels due to their high colour purity and low-cost fabrication,but the toxicity still is a big threat.InP is considered as the most promising cadmium-free material to achieve high performance QLEDs,however,the performance of the InP-based QLEDs is far behind of the cadmium-based counterparts.Here,we report high efficiency InP-based QLEDs with more than 20%of external quantum efficiency(EQE)by suppressing hole injection loss.This suppression is achieved by doping a strong Lewis acid into a Lewis base poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)to form a Lewis acid-base adduct hole-transport layer(HTL),which improves the hole mobility of the HTL,reduces the hole transfer barrier between HTL and QDs layer to increase hole transport capability.This eventually leads to a more balanced carrier-injection through accelerating hole-injection to match well with the rate of electron-injection,thus suppressing the hole injection loss in the QLED.The InP-based QLED shows EQE of 20.4%,current efficiency of 25.3 cd·A^(−1),turn-on voltage of 2.0 V,luminance of 24,000 cd·m^(−2).This strategy would be a constructive approach to reduce hole loss for p-n junction optoelectronics.展开更多
Organolead halide perovskite solar ceils have achieved a certified power- conversion efficiency （PCE） of 22.1% and are thus among the most promising candidates for next-generation photovoltaic devices. To date, most...Organolead halide perovskite solar ceils have achieved a certified power- conversion efficiency （PCE） of 22.1% and are thus among the most promising candidates for next-generation photovoltaic devices. To date, most high-efficiency perovskite solar cells have employed arylamine-based hole-transport materials （HTMs）, which are expensive and have a low mobility. The complicated doping procedures and the potentially stability-adverse dopants used in these HTMs are among the major bottlenecks for the commercialization of perovskite solar cells （PSCs）. Herein, we present a polythiophene-based copolymer （PDVT-10） with a hole mobility up to 8.2 cm2-V-l.s-1 and a highest occupied molecular orbital level of -5.28 eV as a hole-transport layer （HTL） for a PSC. A device based on this new HTM exhibited a high PCE of 13.4% under 100 mW-cm-2 illumination, which is one of the highest PCEs reported for the dopant-free polymer-based HTLs. Moreover, PDVT-10 exhibited good solution processability, decent air stability, and thermal stability, making it a promising candidate as an HTM for PSCs.展开更多
目前,在高效率钙钛矿太阳能电池(perovskite solar cells, PSCs)中,金、银等贵金属对电极和昂贵的空穴传输材料已成为标配,导致电池成本较高,严重阻碍了钙钛矿太阳能电池的推广与发展,开发价格低廉的对电极及空穴传输材料迫在眉睫.碳材...目前,在高效率钙钛矿太阳能电池(perovskite solar cells, PSCs)中,金、银等贵金属对电极和昂贵的空穴传输材料已成为标配,导致电池成本较高,严重阻碍了钙钛矿太阳能电池的推广与发展,开发价格低廉的对电极及空穴传输材料迫在眉睫.碳材料具有价格低廉、化学性质稳定、导电性好、空穴提取能力强等优点,近年来以其作为无空穴传输层钙钛矿太阳能电池对电极的研究取得了一定的成果.本文介绍了碳基无空穴传输层钙钛矿太阳能电池的器件结构及工作原理,并以碳材料种类为划分依据,分别综述了石墨/炭黑、碳纳米管、导电碳浆、碳墨、石墨烯等多种碳材料作为钙钛矿太阳能电池对电极的研究进展,指出现有研究工作中存在的局限性,并简要说明该领域未来的发展方向.展开更多
We demonstrate hole-transport-layer-free light-emitting diodes(LEDs) based on solution-processed multiple-quantum-well(MQW) perovskite. The MQW perovskite can self-assemble to a unique structure of vertically graded d...We demonstrate hole-transport-layer-free light-emitting diodes(LEDs) based on solution-processed multiple-quantum-well(MQW) perovskite. The MQW perovskite can self-assemble to a unique structure of vertically graded distribution with two-dimensional layered perovskite covered by three-dimensionallike perovskite at top, which can naturally form a barrier of electron transporting to the anode interface,thereby enhancing the charge capture efficiency. This leads to hole-transport-layer-free MQW perovskite LEDs reaching an external quantum efficiency(EQE) of 9.0% with emission peak at 528 nm, which is over6 times of LEDs based on three-dimensional perovskite with the same device structure, representing the record EQE of hole-transport-layer-free perovskite LED.展开更多
Diphenyl 5 dimethylaminophenyl pyrazoline was successful to use as a hole transport layer in a EL device which was composed with the following configuration: ITO/DPDMP (40?nm) /PTT (40?nm) /Alq(40?nm) /Al. A green lig...Diphenyl 5 dimethylaminophenyl pyrazoline was successful to use as a hole transport layer in a EL device which was composed with the following configuration: ITO/DPDMP (40?nm) /PTT (40?nm) /Alq(40?nm) /Al. A green light with high purity from the terbium complex in the device has been observed.展开更多
An inverted planar heterojunction perovskite solar cell （PSC） is one of the most competitive photovoltaic devices exhibiting a high power conversion efficiency （PCE） and nearly free hysteresis in the voltage-curre...An inverted planar heterojunction perovskite solar cell （PSC） is one of the most competitive photovoltaic devices exhibiting a high power conversion efficiency （PCE） and nearly free hysteresis in the voltage-current output. However, the band alignment between the transport materials and the perovskite absorber has not been optimized, resulting in a lower open-circuit voltage （Voc） than that of regular PSCs. To address this issue, we tune the band alignment in perovskite photovoltaic architecture by introducing bilayer structured transport materials, e.g., the hole transport material poly（ethylenedioxythiophene）：poly（styrene sulfonate） （PEDOT：PSS）/V2Os. In this study, solution processed inorganic V2Ox interlayer is incorporated into PEDOT：PSS for achieving improved film surface properties as well as optical and electrical properties. For example, the work function （WF） was changed from 5.1 to 5.4 eV. A remarkably high PCE of 17.5% with nearly free hysteresis and a stabilized efficiency of 17.1% have been achieved. Electronic impedance spectra （EIS） demonstrate a significant increase in the recombination resistance after introducing the interlayer, associated with the high Voc output value of 1.05 V. Transient photocurrent and photovoltage measurements indicate that a comparable charge transport process and an inhibited recombination process occur in the PSC with the introduction of the V20x interlayer.展开更多
Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the mo...Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the most actively studied hole transport material in p-i-n structured PSCs.However,charge transport in the PEDOT:PSS is limited and inefficient because of its low conductivity with the presence of the weak ionic conductor PSS.In addition,morphology of the underlying PEDOT:PSS layer in PSCs plays a crucial role in determining the optoelectronic quality of the active perovskite absorber layer.This work is focused on realization of a non-wetting conductive surface of hole transport layer suitable for the growth of larger perovskite crystalline domains.This is accomplished by employing a facile solventengineered(ethylene glycol and methanol)approach resulting in removal of the predominant PSS in PEDOT:PSS.The consequence of acquiring larger perovskite crystalline domains was observed in the charge carrier dynamics studies,with the achievement of higher charge carrier lifetime,lower charge transport time and lower transfer impedance in the solvent-engineered PEDOT:PSS-based PSCs.Use of this solventengineered treatment for the fabrication of MAPbI3 PSCs greatly increased the device stability witnessing a power conversion efficiency of 18.18%,which corresponds to^37%improvement compared to the untreated PEDOT:PSS based devices.展开更多
聚[3,4-乙烯二氧噻吩]:聚苯乙烯磺酸盐(PEDOT:PSS)因其制备工艺简单、导电性能良好、成膜均匀及成本低廉等优势,已成为倒置型钙钛矿太阳能电池(perovskite solar cells,PSCs)中空穴传输层的首选材料.然而,由PSS链中的磺酸基团所导致的...聚[3,4-乙烯二氧噻吩]:聚苯乙烯磺酸盐(PEDOT:PSS)因其制备工艺简单、导电性能良好、成膜均匀及成本低廉等优势,已成为倒置型钙钛矿太阳能电池(perovskite solar cells,PSCs)中空穴传输层的首选材料.然而,由PSS链中的磺酸基团所导致的酸性和吸湿性等问题,对PSCs器件的光电性能和长期稳定性都造成了不良影响.针对以上问题,本文采用向PEDOT:PSS溶液中加入适量碱性赖氨酸的方法,利用赖氨酸中的氨基与PSS链中的磺酸基团的中和反应以适度调节PEDOT:PSS的酸性,改善了沉积于其上的钙钛矿薄膜的成膜质量,提高了器件的光电性能和长期稳定性.实验结果表明:使用赖氨酸掺杂的PEDOT:PSS薄膜为空穴传输层(hole transport layer,HTL)制备的倒置型PSCs器件,其开路电压(open circuit voltage,V_(OC))从0.94 V(未掺杂的PEDOT:PSS薄膜为HTL的参考器件)提升至1.04 V,短路电流(short circuit current,J_(SC))从20.81 mA cm^(-2)(参考器件)增加到21.35 mA cm^(-2),光电转换效率(power conversion efficiency,PCE)从15.71%(参考器件)提高到17.65%.此外,将未封装的赖氨酸掺杂的PSCs器件在氮气氛围(25℃)中存储2160 h后,其PCE保持为初始效率的86.54%;而在空气环境(25℃@15%相对湿度)中储存360 h后,其PCE仍能保持初始效率的85.88%.总的说来,将碱性赖氨酸作为掺杂剂引入PEDOT:PSS溶液,不仅能够适度中和PEDOT:PSS的酸性,还能改善钙钛矿薄膜的结晶性能和成膜质量,为实现高效稳定的倒置PSCs提供了一种新的思路.展开更多
基金supported by the National Natural Science Foundation of China (51772135)the Ministry of Education of China (6141A02022516)+4 种基金the Fundamental Research Funds for the Central Universities (11619103)China Postdoctoral Science Foundation (2019M663376)Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2017)the Natural Science Foundation of Guangdong Province, China (2017A020215135 and 2018A030310659)the Science and Technology Program of Guangzhou, China (201804010432)。
文摘Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite-based self-powered photodetectors containing inorganic copper thiocyanate(CuSCN) as hole-transport layers(HTLs) are successfully fabricated and applied for weak light imaging,which is the first report on the weak light imaging application of all-inorganic lead-free perovskite photodetectors. CuSCN films with favorable optical property and hole extraction capability are prepared via a cost efficient and fast solvent removal method, demonstrating the potential for high-performance perovskite-based devices as transparent components. It is revealed that the band alignment of the device is effectively optimized with the presence of CuSCN HTLs,which can availably transport holes while block electrons at the Cs2AgBiBr6/CuSCN interface, resulting in remarkable improvement of photoresponse performance. The responsivity and detectivity are 0.34 A W^-1 and 1.03×10^13 Jones,respectively. In particular, the light current has a boost of almost 10 times. Furthermore, the photodetectors are integrated into a self-built light detection imaging system utilizing the focused laser scanning imaging mode. With illumination of as low as 5 nW cm^-2(405 nm), the image involving graphics and words with a size of 5 cm×5 cm can still be distinctly recognized. These results suggest the promising potential of all-inorganic perovskite-based devices for weak light detection and imaging applications.
基金the Beijing Municipal Natural Science Foundation(No.2222061)the National Natural Science Foundation of China(Nos.51961135107 and 51774034)the National Key Research and Development Program of China(No.2017YFE0119700).
文摘Solution-processed cadmium-based quantum dots(QDs)light-emitting diodes(QLEDs)have shown promising for high-definition display panels due to their high colour purity and low-cost fabrication,but the toxicity still is a big threat.InP is considered as the most promising cadmium-free material to achieve high performance QLEDs,however,the performance of the InP-based QLEDs is far behind of the cadmium-based counterparts.Here,we report high efficiency InP-based QLEDs with more than 20%of external quantum efficiency(EQE)by suppressing hole injection loss.This suppression is achieved by doping a strong Lewis acid into a Lewis base poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)to form a Lewis acid-base adduct hole-transport layer(HTL),which improves the hole mobility of the HTL,reduces the hole transfer barrier between HTL and QDs layer to increase hole transport capability.This eventually leads to a more balanced carrier-injection through accelerating hole-injection to match well with the rate of electron-injection,thus suppressing the hole injection loss in the QLED.The InP-based QLED shows EQE of 20.4%,current efficiency of 25.3 cd·A^(−1),turn-on voltage of 2.0 V,luminance of 24,000 cd·m^(−2).This strategy would be a constructive approach to reduce hole loss for p-n junction optoelectronics.
文摘Organolead halide perovskite solar ceils have achieved a certified power- conversion efficiency （PCE） of 22.1% and are thus among the most promising candidates for next-generation photovoltaic devices. To date, most high-efficiency perovskite solar cells have employed arylamine-based hole-transport materials （HTMs）, which are expensive and have a low mobility. The complicated doping procedures and the potentially stability-adverse dopants used in these HTMs are among the major bottlenecks for the commercialization of perovskite solar cells （PSCs）. Herein, we present a polythiophene-based copolymer （PDVT-10） with a hole mobility up to 8.2 cm2-V-l.s-1 and a highest occupied molecular orbital level of -5.28 eV as a hole-transport layer （HTL） for a PSC. A device based on this new HTM exhibited a high PCE of 13.4% under 100 mW-cm-2 illumination, which is one of the highest PCEs reported for the dopant-free polymer-based HTLs. Moreover, PDVT-10 exhibited good solution processability, decent air stability, and thermal stability, making it a promising candidate as an HTM for PSCs.
文摘目前,在高效率钙钛矿太阳能电池(perovskite solar cells, PSCs)中,金、银等贵金属对电极和昂贵的空穴传输材料已成为标配,导致电池成本较高,严重阻碍了钙钛矿太阳能电池的推广与发展,开发价格低廉的对电极及空穴传输材料迫在眉睫.碳材料具有价格低廉、化学性质稳定、导电性好、空穴提取能力强等优点,近年来以其作为无空穴传输层钙钛矿太阳能电池对电极的研究取得了一定的成果.本文介绍了碳基无空穴传输层钙钛矿太阳能电池的器件结构及工作原理,并以碳材料种类为划分依据,分别综述了石墨/炭黑、碳纳米管、导电碳浆、碳墨、石墨烯等多种碳材料作为钙钛矿太阳能电池对电极的研究进展,指出现有研究工作中存在的局限性,并简要说明该领域未来的发展方向.
基金financially supported by the Major Research Plan of the National Natural Science Foundation of China (No.91733302)the National Natural Science Foundation of China (Nos.61875084,61922041,61961160733,61974126,51902273)+4 种基金the National Science Fund for Distinguished Young Scholars (No.61725502)the Natural Science Foundation of Jiangsu Province,China (No.BK20180085)the Major Program of Natural Science Research of Jiangsu Higher Education Institutions of China (No.19KJA520004)the Joint Research Funds of the Department of Science & Technology of Shaanxi Province and NPU (No.2020GXLH-Z-024)the Synergetic Innovation Center for Organic Electronics and Information Displays,a part of this research was undertaken on the SAXS/WAXS beamline at the Australian Synchrotron。
文摘We demonstrate hole-transport-layer-free light-emitting diodes(LEDs) based on solution-processed multiple-quantum-well(MQW) perovskite. The MQW perovskite can self-assemble to a unique structure of vertically graded distribution with two-dimensional layered perovskite covered by three-dimensionallike perovskite at top, which can naturally form a barrier of electron transporting to the anode interface,thereby enhancing the charge capture efficiency. This leads to hole-transport-layer-free MQW perovskite LEDs reaching an external quantum efficiency(EQE) of 9.0% with emission peak at 528 nm, which is over6 times of LEDs based on three-dimensional perovskite with the same device structure, representing the record EQE of hole-transport-layer-free perovskite LED.
文摘Diphenyl 5 dimethylaminophenyl pyrazoline was successful to use as a hole transport layer in a EL device which was composed with the following configuration: ITO/DPDMP (40?nm) /PTT (40?nm) /Alq(40?nm) /Al. A green light with high purity from the terbium complex in the device has been observed.
基金The authors are grateful to Dr. Xinchen Li of Zolix Instruments Co., Ltd. for transient measurements and Prof. Jinglin Xie for XPS measurements. This work was supported by the National Basic Research Program of China （No. 2011CB933303） and the National Natural Science Foundation of China （NSFC） （Nos. 21321001 and 21371012）. This work was also supported by the ＂Thousand Youth Talents Plan＂, China.
文摘An inverted planar heterojunction perovskite solar cell （PSC） is one of the most competitive photovoltaic devices exhibiting a high power conversion efficiency （PCE） and nearly free hysteresis in the voltage-current output. However, the band alignment between the transport materials and the perovskite absorber has not been optimized, resulting in a lower open-circuit voltage （Voc） than that of regular PSCs. To address this issue, we tune the band alignment in perovskite photovoltaic architecture by introducing bilayer structured transport materials, e.g., the hole transport material poly（ethylenedioxythiophene）：poly（styrene sulfonate） （PEDOT：PSS）/V2Os. In this study, solution processed inorganic V2Ox interlayer is incorporated into PEDOT：PSS for achieving improved film surface properties as well as optical and electrical properties. For example, the work function （WF） was changed from 5.1 to 5.4 eV. A remarkably high PCE of 17.5% with nearly free hysteresis and a stabilized efficiency of 17.1% have been achieved. Electronic impedance spectra （EIS） demonstrate a significant increase in the recombination resistance after introducing the interlayer, associated with the high Voc output value of 1.05 V. Transient photocurrent and photovoltage measurements indicate that a comparable charge transport process and an inhibited recombination process occur in the PSC with the introduction of the V20x interlayer.
基金supported by NSF MRI (1428992)NASA EPSCoR (NNX15AM83A)+3 种基金U.S.–Egypt Science and Technology (S&T) Joint FundSDBoR R&D ProgramEDA University Center Program (ED18DEN3030025)supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC0206CH11357.
文摘Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the most actively studied hole transport material in p-i-n structured PSCs.However,charge transport in the PEDOT:PSS is limited and inefficient because of its low conductivity with the presence of the weak ionic conductor PSS.In addition,morphology of the underlying PEDOT:PSS layer in PSCs plays a crucial role in determining the optoelectronic quality of the active perovskite absorber layer.This work is focused on realization of a non-wetting conductive surface of hole transport layer suitable for the growth of larger perovskite crystalline domains.This is accomplished by employing a facile solventengineered(ethylene glycol and methanol)approach resulting in removal of the predominant PSS in PEDOT:PSS.The consequence of acquiring larger perovskite crystalline domains was observed in the charge carrier dynamics studies,with the achievement of higher charge carrier lifetime,lower charge transport time and lower transfer impedance in the solvent-engineered PEDOT:PSS-based PSCs.Use of this solventengineered treatment for the fabrication of MAPbI3 PSCs greatly increased the device stability witnessing a power conversion efficiency of 18.18%,which corresponds to^37%improvement compared to the untreated PEDOT:PSS based devices.
文摘聚[3,4-乙烯二氧噻吩]:聚苯乙烯磺酸盐(PEDOT:PSS)因其制备工艺简单、导电性能良好、成膜均匀及成本低廉等优势,已成为倒置型钙钛矿太阳能电池(perovskite solar cells,PSCs)中空穴传输层的首选材料.然而,由PSS链中的磺酸基团所导致的酸性和吸湿性等问题,对PSCs器件的光电性能和长期稳定性都造成了不良影响.针对以上问题,本文采用向PEDOT:PSS溶液中加入适量碱性赖氨酸的方法,利用赖氨酸中的氨基与PSS链中的磺酸基团的中和反应以适度调节PEDOT:PSS的酸性,改善了沉积于其上的钙钛矿薄膜的成膜质量,提高了器件的光电性能和长期稳定性.实验结果表明:使用赖氨酸掺杂的PEDOT:PSS薄膜为空穴传输层(hole transport layer,HTL)制备的倒置型PSCs器件,其开路电压(open circuit voltage,V_(OC))从0.94 V(未掺杂的PEDOT:PSS薄膜为HTL的参考器件)提升至1.04 V,短路电流(short circuit current,J_(SC))从20.81 mA cm^(-2)(参考器件)增加到21.35 mA cm^(-2),光电转换效率(power conversion efficiency,PCE)从15.71%(参考器件)提高到17.65%.此外,将未封装的赖氨酸掺杂的PSCs器件在氮气氛围(25℃)中存储2160 h后,其PCE保持为初始效率的86.54%;而在空气环境(25℃@15%相对湿度)中储存360 h后,其PCE仍能保持初始效率的85.88%.总的说来,将碱性赖氨酸作为掺杂剂引入PEDOT:PSS溶液,不仅能够适度中和PEDOT:PSS的酸性,还能改善钙钛矿薄膜的结晶性能和成膜质量,为实现高效稳定的倒置PSCs提供了一种新的思路.
