Revealing a Zinc Oxide/Perovskite Luminescence QuenchingMechanism Targeting Low-Roll-offLight-Emitting Diodes
Revealing a Zinc Oxide/Perovskite Luminescence QuenchingMechanism Targeting Low-Roll-offLight-Emitting Diodes
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DOI：
10.1021/acs.jpclett.2c00564
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发表时间：
2022-04-07
影响因子：
5.7
通讯作者：
Sun, Baoquan
中科院分区：
文献类型：
--
作者：
Bai, Guilin;Zou, Yatao;Sun, Baoquan
平衡电荷注入是实现钙钛矿发光二极管（PeLEDs）在高亮度下具有低效率滚降的关键。使用具有高电子迁移率的氧化锌（ZnO）作为电荷传输层是理想的；然而，钙钛矿在ZnO上的光致发光（PL）猝灭总是会发生。在此，对ZnO上的准二维钙钛矿进行了研究，以揭示PL猝灭机制，这主要归因于ZnO薄膜上铵阳离子的去质子化以及低维钙钛矿相的分解。令人惊讶的是，依赖于晶面的PL猝灭结果表明，去质子化速率与ZnO表面的晶体取向密切相关。我们开发了一种通过在ZnO薄膜上沉积原子层Al₂O₃来抑制钙钛矿PL猝灭的策略。因此，实现了一种高效的倒置PeLED，其最大外量子效率为17.7%，并且在高电流密度下效率滚降不太明显。
Balanced charge injection is key to achieving perovskite light-emitting diodes(PeLEDs) with a low efficiency roll-offat a high brightness. The use of zinc oxide (ZnO)with a high electron mobility as the charge transport layers is desirable; however,photoluminescence (PL) quenching of a perovskite on ZnO always occurs. Here, a quasi-two-dimensional perovskite on ZnO is explored to uncover the PL quenching mechanism,mainly ascribed to the deprotonation of ammonium cations on the ZnOfilm in associationwith the decomposition of low-dimensional perovskite phases. Surprisingly, crystal plane-dependent PL quenching results indicate that the deprotonation rate strongly correlateswith the crystal orientation of the ZnO surface. We developed a strategy for suppressingperovskite PL quenching by incorporating an atomic layer deposited Al2O3onto the ZnOfilm. Consequently, an efficient inverted PeLED was achieved with a maximum externalquantum efficiency of 17.7% and a less discernible efficiency roll-offat a high currentdensity.