Peng Chencheng, He Zhiyuan, Guo Runda, Li Xin, Chen Hongting, Chen Ben, Sun Liang, Chen Jiangshan, Wang Lei
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
ACS Appl Mater Interfaces. 2023 Mar 29;15(12):15768-15774. doi: 10.1021/acsami.3c00376. Epub 2023 Mar 16.
Multisource coevaporation is such a promising method for the preparation of perovskite films. However, there is limited research about the effects of the buried interface on thermal-evaporated perovskite light-emitting diodes (PeLEDs). In this study, the effects of buried interfaces on thermal-evaporated all-inorganic perovskite films are systematically investigated. It is found that the low-surface-energy buried interface promotes the formation of columnar grain by suppressing heterogeneous nucleation, and functional groups on the high-surface-energy interface have a significant effect on the actual element ratio of the film. The substrate temperature can affect the nucleation and film-formation kinetics of the columnar grains. As a result of the synergistic strategy, a peak external quantum efficiency (EQE) of 8.6% is achieved in the green PeLEDs with a stable emission peak at 516 nm, which is among the best thermal-evaporated PeLEDs reported. This work provides an insight into the preparation of perovskites by thermal evaporation and builds the groundwork for future studies.
多源共蒸发是一种极具前景的制备钙钛矿薄膜的方法。然而，关于埋入界面热蒸发钙钛矿发光二极管（PeLED）的影响的研究有限。在本研究中，系统地研究了埋入界面对热蒸发全无机钙钛矿薄膜的影响。研究发现，低表面能埋入界面通过抑制异质形核促进柱状晶粒的形成，高表面能界面上的官能团对薄膜的实际元素比例有显著影响。衬底温度会影响柱状晶粒的形核和成膜动力学。通过协同策略，在绿色PeLED中实现了8.6%的峰值外量子效率（EQE），发射峰稳定在516nm，这是所报道的最佳热蒸发PeLED之一。这项工作为热蒸发制备钙钛矿提供了见解，并为未来的研究奠定了基础。
