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
卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。...卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。到目前为止,Sn、Ge、Sb、Bi等材料都已得到研究,其中铋基钙钛矿因其稳定、无毒和宽带隙等特性成为候选材料之一。影响PDs性能的因素很多,其中抑制暗电流是提升器件性能的重要手段之一。本文通过溶液旋涂无机化合物CuSCN取代传统PEDOT∶PSS作为空穴传输层(HTL),制备了结构为ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag的p-i-n型光电探测器。CuSCN最低未占分子轨道(LUMO)能级为-1.5 e V,与ITO电子注入势垒高达3.3 e V,远高于PEDOT∶PSS与ITO的电子注入势垒(1.8 e V),反向偏压下工作更能有效阻挡电子从ITO电极的注入,因此降低了探测器的暗电流。器件在自供电条件425 nm单色光照射下光电流达6.87×10^(-6)A,暗电流低至3.52×10^(-11)A,开关比超过10~5,相比于基于PEDOT∶PSS空穴传输层的探测器提升了2个数量级。此外,该探测器的上升和下降时间都小于0.12 s,均优于基于PEDOT∶PSS空穴传输层的探测器,这可归因于CuSCN比PEDOT∶PSS具有更高的载流子传输迁移率。结果表明,ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag结构的光电探测器具有自供电、高开关比、稳定、无毒等优点,为实现商业化提供了一种可行策略。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
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
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.
文摘卤化铅钙钛矿具有高光吸收系数、长载流子扩散长度和高荧光量子效率等优异光电特性,成为当下光电探测器(PDs)研究领域的热点。但卤化铅钙钛矿的高生物毒性和低环境稳定性制约了该类器件的发展和应用,因此寻找低毒稳定的材料尤为重要。到目前为止,Sn、Ge、Sb、Bi等材料都已得到研究,其中铋基钙钛矿因其稳定、无毒和宽带隙等特性成为候选材料之一。影响PDs性能的因素很多,其中抑制暗电流是提升器件性能的重要手段之一。本文通过溶液旋涂无机化合物CuSCN取代传统PEDOT∶PSS作为空穴传输层(HTL),制备了结构为ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag的p-i-n型光电探测器。CuSCN最低未占分子轨道(LUMO)能级为-1.5 e V,与ITO电子注入势垒高达3.3 e V,远高于PEDOT∶PSS与ITO的电子注入势垒(1.8 e V),反向偏压下工作更能有效阻挡电子从ITO电极的注入,因此降低了探测器的暗电流。器件在自供电条件425 nm单色光照射下光电流达6.87×10^(-6)A,暗电流低至3.52×10^(-11)A,开关比超过10~5,相比于基于PEDOT∶PSS空穴传输层的探测器提升了2个数量级。此外,该探测器的上升和下降时间都小于0.12 s,均优于基于PEDOT∶PSS空穴传输层的探测器,这可归因于CuSCN比PEDOT∶PSS具有更高的载流子传输迁移率。结果表明,ITO/CuSCN/Cs_(3)Bi_(2)I_(6)Br_(3)/Zn O/Ag结构的光电探测器具有自供电、高开关比、稳定、无毒等优点,为实现商业化提供了一种可行策略。
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.
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.
