Light-emitting diodes based on halide perovskites have recently reached external quantum efficiencies of over 20%. However, the performance of visible perovskite light-emitting diodes has been hindered by non-radiative recombination losses and limited options for charge-transport materials that are compatible with perovskite deposition. Here, we report efficient, green electroluminescence from mixed-dimensional perovskites deposited on a thin (~1 nm) lithium fluoride layer on an organic semiconductor hole-transport layer. The highly polar dielectric interface acts as an effective template for forming high-quality bromide perovskites on otherwise incompatible hydrophobic charge-transport layers. The control of crystallinity and dimensionality of the perovskite layer is achieved by using tetraphenylphosphonium chloride as an additive, leading to external photoluminescence quantum efficiencies of around 65%. With this approach, we obtain light-emitting diodes with external quantum efficiencies of up to 19.1% at high brightness (>1,500 cd m⁻²).

最近，基于卤化物钙钛矿的发光二极管的外部量子效率已超过20％。然而，可见钙钛矿发光二极管的性能受到非辐射复合损失和与钙钛矿沉积相容的电荷传输材料的有限选择的阻碍。在这里，我们报道了由沉积在有机半导体空穴传输层上的氟化锂薄层（〜1 nm）上的混合尺寸钙钛矿形成的高效绿色电致发光。高极性介电界面是在不相容的疏水性电荷传输层上形成高质量溴化钙钛矿的有效模板。钙钛矿层的结晶度和尺寸控制是通过使用四苯基氯化phosph作为添加剂来实现的，导致外部光致发光的量子效率约为65％。通过这种方法，我们获得了在高亮度（> 1,500 cd m）下具有高达19.1％的外部量子效率的发光二极管^-2）。