Tang Jun, Zhang Guoshuai, Wang Chenming, Deng Liangliang, Zhu Xixiang, Yu Haomiao, Wang Kai, Li Jinpeng
Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing 100044, China.
Center of Micro-Nano System, School of Information Science and Technology, Fudan University, Shanghai 200438, China.
J Phys Chem Lett. 2024 Feb 1;15(4):1112-1120. doi: 10.1021/acs.jpclett.3c03417. Epub 2024 Jan 23.
Quasi-two-dimensional (2D) perovskite light-emitting diodes are promising light sources for color display and lighting. However, poor carrier injection and transport between the bottom hole transport layer (HTL) and perovskite limit the device performance. Here we demonstrate a simple and effective way to modify the HTL for enhancing the performance of perovskite light-emitting diodes (PeLEDs). An electrolyte KSO is used to mix with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as the hole transport layer. The K doping helped the quasi-2D perovskite phases grow vertically along the interface of the PEDOT:PSS, fine-modulate the phase distribution, and simultaneously reduce the defect density of quasi-2D perovskites. It also significantly reduced the exciton quenching and injection barrier at PEDOT:PSS and quasi-2D perovskite interface. The optimized green PeLEDs with the KSO doped PEDOT:PSS HTL showed a maximum luminance of 17185 cd/m which is almost 4.7 times brighter than the control one, with a maximum external quantum efficiency of 18.64%.
准二维（2D）钙钛矿发光二极管是用于彩色显示和照明的有前景的光源。然而，底部空穴传输层（HTL）与钙钛矿之间不良的载流子注入和传输限制了器件性能。在此，我们展示了一种简单有效的方法来修饰HTL以提高钙钛矿发光二极管（PeLEDs）的性能。使用电解质KSO与聚（3,4 - 乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）混合作为空穴传输层。K掺杂有助于准二维钙钛矿相沿着PEDOT:PSS的界面垂直生长，精细调节相分布，并同时降低准二维钙钛矿的缺陷密度。它还显著降低了PEDOT:PSS与准二维钙钛矿界面处的激子猝灭和注入势垒。采用KSO掺杂的PEDOT:PSS HTL的优化绿色PeLEDs显示出最大亮度为17185 cd/m²，几乎比对照器件亮4.7倍，最大外量子效率为18.64%。
