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超亮、高效、稳定的钙钛矿发光二极管
作者:小柯机器人 发布时间:2022/11/11 17:00:06

韩国首尔国立大学Lee Tae-Woo开发了超亮、高效、稳定的钙钛矿发光二极管。相关研究成果于2022年11月9日发表在《自然》。

金属卤化物钙钛矿作为下一代发光材料,由于其优异的发射性能,具有窄带发射,因此受到了广泛关注。然而,钙钛矿发光二极管(PeLEDs),无论其材料类型(多晶或纳米晶)如何,都没有同时实现高亮度、高效率和长寿命,因为它们受到与每种钙钛矿材料中的电荷传输和限制之间的特性权衡相关内在限制的影响。

该文中,研究人员报道了由核/壳钙钛矿纳米晶体制成的超亮、高效和稳定的PeLED,其尺寸约为10nm,使用苄基膦酸(BPA)添加剂与三维(3D)多晶钙钛矿膜的简单原位反应获得。在反应过程中,大型3D晶体分裂成纳米晶体,BPA围绕纳米晶体,实现了强载流子限制。BPA壳通过形成共价键钝化欠配位的铅原子,从而大大降低陷阱密度,同时保持3D钙钛矿良好的电荷传输特性。

同时,研究证明了高效、明亮和稳定的PeLED,其最大亮度约为470000cdm-2,最大外部量子效率为28.9%(40个器件的平均值为25.2±1.6%),最大电流效率为151cdA-1,在1000cdm-2下的半衰期为520h(估计在100cdm-2下半衰期>30000h)。

研究工作展示了PeLEDs在未来显示产业中商业化的可能性。

附:英文原文

Title: Ultra-bright, efficient and stable perovskite light-emitting diodes

Author: Kim, Joo Sung, Heo, Jung-Min, Park, Gyeong-Su, Woo, Seung-Je, Cho, Changsoon, Yun, Hyung Joong, Kim, Dong-Hyeok, Park, Jinwoo, Lee, Seung-Chul, Park, Sang-Hwan, Yoon, Eojin, Greenham, Neil C., Lee, Tae-Woo

Issue&Volume: 2022-11-09

Abstract: Metal halide perovskites are attracting a lot of attention as next-generation light-emitting materials owing to their excellent emission properties, with narrow band emission1,2,3,4. However, perovskite light-emitting diodes (PeLEDs), irrespective of their material type (polycrystals or nanocrystals), have not realized high luminance, high efficiency and long lifetime simultaneously, as they are influenced by intrinsic limitations related to the trade-off of properties between charge transport and confinement in each type of perovskite material5,6,7,8. Here, we report an ultra-bright, efficient and stable PeLED made of core/shell perovskite nanocrystals with a size of approximately 10nm, obtained using a simple in situ reaction of benzylphosphonic acid (BPA) additive with three-dimensional (3D) polycrystalline perovskite films, without separate synthesis processes. During the reaction, large 3D crystals are split into nanocrystals and the BPA surrounds the nanocrystals, achieving strong carrier confinement. The BPA shell passivates the undercoordinated lead atoms by forming covalent bonds, and thereby greatly reduces the trap density while maintaining good charge-transport properties for the 3D perovskites. We demonstrate simultaneously efficient, bright and stable PeLEDs that have a maximum brightness of approximately 470,000cdm2, maximum external quantum efficiency of 28.9% (average=25.2±1.6% over 40 devices), maximum current efficiency of 151cdA1 and half-lifetime of 520h at 1,000cdm2 (estimated half-lifetime >30,000h at 100cdm2). Our work sheds light on the possibility that PeLEDs can be commercialized in the future display industry.

DOI: 10.1038/s41586-022-05304-w

Source: https://www.nature.com/articles/s41586-022-05304-w

期刊信息
Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:42.778
官方网址:http://www.nature.com/