含氟膦氧衍生物修饰的纯蓝光钙钛矿发光二极管

Pure Blue Perovskite Light‑Emitting Diodes Modified with Fluorine‑Containing Phosphine Oxide Derivatives

实现高效蓝色电致发光是钙钛矿发光二极管(PeLEDs)商业应用的关键挑战,特别是波长为465~475 nm的纯蓝光。蓝光PeLEDs的低效率主要源于混合卤素策略导致的高缺陷密度和降维策略导致的载流子注入困难。本文以氯/溴混合卤素准二维钙钛矿为研究对象,探究了小分子添加剂膦氧衍生物((五氟苯基)甲基)二苯基氧化膦(PFPO)在钙钛矿前驱体溶液中的作用机理及其对钙钛矿薄膜形貌、光学和器件性能的影响。实验结果显示,PFPO修饰后的钙钛矿薄膜光致发光强度和寿命均有增加,说明PFPO具有良好的缺陷钝化能力。紫外-可见光吸收光谱证实修饰后薄膜中小n相吸收强度明显降低,说明小n相得到了显著抑制,减少了非辐射复合路径,同时有利于激子能量转移。器件结果表明,PFPO处理后的PeLEDs器件最大外量子效率从1.83%提升到3.62%,发光峰位于466 nm,对应的CIE为(0.123,0.079),与标准蓝光CIE坐标(0.131,0.046)接近。

Achieving efficient blue electroluminescence(EL)is a crucial challenge for the commercial application of perovskite light-emitting diodes(LEDs),especially for pure blue light with wavelengths of 465~475 nm.The main factors contributing to the low efficiency of blue light perovskite LEDs are the high defect density and difficulties in carrier injection induced by the mixed halogen and dimensionality reduction strategies.Herein,we propose an approach for achieving high-performance pure-blue perovskite LEDs by incorporating a fluorine-containing phosphine oxide derivative(PFPO).This incorporation significantly suppresses the non-radiative recombination and fine-tunes the low-dimensional phase distribution of quasi-2D perovskites.The device results reveal that the maximum external quantum efficiency(EQE)of PFPO-treated perovskite LEDs has increased from 1.83%to 3.62%.The emission peak is located at 466 nm,corresponding to CIE of(0.123,0.079),which is close to the International Telecommunication Union(ITU)Rec.2020 blue standard(0.131,0.046).