Lin Chunyan, Chen Ping, Xiong ZiYang, Liu Debei, Wang Gang, Meng Yan, Song Qunliang
Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing, 400715, People's Republic of China. Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy, Chongqing, 400715, People's Republic of China.
Nanotechnology. 2018 Feb 16;29(7):075203. doi: 10.1088/1361-6528/aa9fa3.
Organic-inorganic hybrid perovskites have attracted great attention in the field of lighting and display due to their very high color purity and low-cost solution-process. Researchers have done a lot of work in realizing high performance electroluminescent devices. However, the current efficiency (CE) of methyl-ammonium lead halide perovskite light-emitting diodes (PeLEDs) still needs to be improved. Herein, we demonstrate the enhanced performance of PeLEDs through introducing an ultrathin poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) buffer layer between poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and CHNHPbBr perovskite. Compared to the reference device without PFO, the optimal device luminous intensity, the maximum CE, and the maximum external quantum efficiency increases from 8139 cd m to 30 150 cd m, from 7.20 cd A (at 6.8 V) to 10.05 cd A (at 6.6 V), and from 1.73% to 2.44%, respectively. The ultrathin PFO layer not only reduces the exciton quenching at the interface between the hole-transport layer and emission layer, but also passivates the shallow-trap ensure increasing hole injection, as well as increases the coverage of perovskite film.
有机-无机杂化钙钛矿因其极高的色纯度和低成本的溶液加工工艺，在照明和显示领域引起了极大关注。研究人员在实现高性能电致发光器件方面做了大量工作。然而，甲基铵铅卤化物钙钛矿发光二极管（PeLEDs）的当前效率（CE）仍有待提高。在此，我们通过在聚（3,4-乙烯二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）和CH₃NH₃PbBr₃钙钛矿之间引入超薄的聚（9,9-二正辛基芴-2,7-二基）（PFO）缓冲层，展示了PeLEDs性能的增强。与没有PFO的参考器件相比，优化后的器件发光强度、最大CE和最大外量子效率分别从8139 cd m⁻²提高到30150 cd m⁻²，从7.20 cd A⁻¹（在6.8 V时）提高到10.05 cd A⁻¹（在6.6 V时），以及从1.73%提高到2.44%。超薄的PFO层不仅减少了空穴传输层和发射层之间界面处的激子猝灭，还钝化了浅陷阱，确保增加空穴注入，并增加了钙钛矿薄膜的覆盖率。
