Zhu Zhaohua, Wu Yan, Li Yang, Zeng Zixin, Tsang Sai-Wing, Guan Zhiqiang, Lee Chun-Sing
Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China.
Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China.
ACS Appl Mater Interfaces. 2022 May 4;14(17):19774-19784. doi: 10.1021/acsami.1c24561. Epub 2022 Apr 20.
While humidity treatment has been employed for enhancing the performance of perovskite solar cells and light-emitting diodes (LEDs), only very limited success has been achieved in quasi-two-dimensional (2D) perovskite LEDs (PeLEDs). Here, for the first time, we demonstrate more than one order of magnitude enhancement of the external quantum efficiency (EQE) and electroluminescence (EL) intensity in blue CsPb(Cl/Br) PeLEDs with an organic cation of 2,2-(ethylenedioxy)bis(ethylammonium) (EDBE). Upon humidity treatment, the crystallinity of the three-dimensional (3D) perovskite phase in the EDBE-based perovskite is improved, contributing to an enhancement of photoluminescence quantum yield (PLQY). This work suggests that elaborately modulating the molecular structure of large cations under humidity treatment can serve as an effective strategy to improve the performance of quasi-2D PeLEDs.
虽然湿度处理已被用于提高钙钛矿太阳能电池和发光二极管（LED）的性能，但在准二维（2D）钙钛矿发光二极管（PeLED）方面仅取得了非常有限的成功。在此，我们首次展示了采用2,2-（乙二氧基）双（乙铵）（EDBE）有机阳离子的蓝色CsPb(Cl/Br) PeLED的外量子效率（EQE）和电致发光（EL）强度提高了一个多数量级。经过湿度处理后，基于EDBE的钙钛矿中三维（3D）钙钛矿相的结晶度得到改善，有助于提高光致发光量子产率（PLQY）。这项工作表明，在湿度处理下精心调节大阳离子的分子结构可以作为提高准二维PeLED性能的有效策略。
