Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, U.K.
ACS Nano. 2023 Feb 28;17(4):3289-3300. doi: 10.1021/acsnano.2c04786. Epub 2023 Feb 15.
Halide perovskite light-emitting diodes (PeLEDs) exhibit great potential for use in next-generation display technologies. However, scale-up will be challenging due to the requirement of very thin transport layers for high efficiencies, which often present spatial inhomogeneities from improper wetting and drying during solution processing. Here, we show how a thin AlO layer grown by atomic layer deposition can be used to preferentially cover regions of imperfect hole transport layer deposition and form an intermixed composite with the organic transport layer, allowing hole conduction and injection to persist through the organic hole transporter. This has the dual effect of reducing nonradiative recombination at the heterojunction and improving carrier selectivity, which we infer to be due to the inhibition of direct contact between the indium tin oxide and perovskite layers. We observe an immediate improvement in electroluminescent external quantum efficiency in our p-i-n LEDs from an average of 9.8% to 13.5%, with a champion efficiency of 15.0%. The technique uses industrially available equipment and can readily be scaled up to larger areas and incorporated in other applications such as thin-film photovoltaic cells.
卤化物钙钛矿发光二极管（PeLEDs）在下一代显示技术中具有巨大的应用潜力。然而，由于高效率需要非常薄的传输层，这在溶液处理过程中经常会因润湿性和干燥性不当而导致空间不均匀，因此扩大规模将具有挑战性。在这里，我们展示了如何使用原子层沉积生长的薄 AlO 层来优先覆盖不完美的空穴传输层沉积区域，并与有机传输层形成混合复合材料，从而允许空穴通过有机空穴传输体进行传导和注入。这具有双重效果，即减少异质结处的非辐射复合，并改善载流子选择性，我们推断这是由于抑制了铟锡氧化物和钙钛矿层之间的直接接触。我们观察到我们的 p-i-n LED 的电致发光外量子效率立即从平均 9.8%提高到 13.5%，其中一个效率最高达到 15.0%。该技术使用工业上可用的设备，并且可以很容易地扩展到更大的面积，并应用于其他应用，如薄膜光伏电池。
