Recently, surface passivation has been proved to be an essential approach for obtaining efficient and stable perovskite light-emitting diodes (Pero-LEDs). Phosphine oxides performed well as passivators in many reports. However, the most commonly used phosphine oxides are insulators, which may inhibit carrier transport between the perovskite emitter and charge-transporter layers, limiting the corresponding device performance. Here, 2,7-bis(diphenylphosphoryl)-9,9′-spirobifluorene (SPPO13), a conductive molecule with two phosphine oxide functional groups, is introduced to modify the perovskite emitting layer. The bifunctional SPPO13 can passivate the nonradiative defects of perovskite and promote electron injection at the interface of perovskite emitter and electron-transporter layers. As a result, the corresponding Pero-LEDs obtain a maximum external quantum efficiency (EQE) of 22.3%. In addition, the Pero-LEDs achieve extremely high brightness with a maximum of around 190 000 cd/m².

中文翻译：

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导电氧化膦钝化剂可实现高效钙钛矿发光二极管

最近，表面钝化已被证明是获得高效稳定的钙钛矿发光二极管（Pero-LED）的重要方法。在许多报告中，氧化膦作为钝化剂表现良好。然而，最常用的氧化膦是绝缘体，它可能会抑制钙钛矿发射极和电荷传输层之间的载流子传输，从而限制相应的器件性能。在这里，引入了具有两个氧化膦官能团的导电分子 2,7-bis(diphenylphosphoryl)-9,9'-spirobifluorene (SPPO13) 来修饰钙钛矿发光层。双功能 SPPO13 可以钝化钙钛矿的非辐射缺陷，并促进钙钛矿发射极和电子传输层界面的电子注入。因此，相应的 Pero-LED 获得 22.3% 的最大外部量子效率 (EQE)。此外，Pero-LED 可实现极高的亮度，最大亮度约为 190 000 cd/m² .