中国吉林大学纪文宇团队研究了高效量子点发光二极管的ZnO再结晶。2025年5月15日出版的《光：科学与应用》杂志发表了这项成果。

ZnO纳米粒子由于其优异的电子输运特性，在量子点发光二极管（QLED）的发展中起着至关重要的作用。虽然ZnO的电导率是由载流子的密度和迁移率决定的，但一个以前被忽视的问题是，ZnO中过多的载流子密度会导致量子点/ZnO界面处的非辐射俄热复合。理想的电子传输层应同时具有高迁移率和低载流子密度。

研究组通过操作再结晶在ZnO NP薄膜中实现了这种输运性质，这一过程是由酸性条件下阴极上的Al离子扩散引发的。这种扩散诱导相邻ZnO纳米粒子聚结，形成缺陷钝化的长程ZnO晶体。在QLED中作为电子传输层，与传统ZnO电子传输层的器件相比，重结晶ZnO NPs的外量子效率从17.2%提高到33.7%。这些发现为高性能光电器件的电荷传输材料的开发提供了有价值的见解。

附：英文原文

Title: Operando ZnO recrystallization for efficient quantum-dot light-emitting diodes

Author: Wang, Song, Liu, Shihao, Wang, Ting, Bai, Jialin, Peng, Jingyu, Zhang, Hanzhuang, Xie, Wenfa, Ji, Wenyu

Issue&Volume: 2025-05-15

Abstract: ZnO nanoparticles (NPs) play a crucial role in advancing quantum-dot light-emitting diodes (QLEDs) because of their excellent electron transport properties. While the conductivity of ZnO is determined by both the density and mobility of charge carriers, a previously overlooked problem is that excessive carrier density in ZnO can lead to nonradiative Auger recombination at the quantum-dot/ZnO interface. An ideal electron transport layer should possess both high mobility and low carrier density. Here, we achieve such transport properties in ZnO NP films through operando recrystallization, a process triggered by the diffusion of Al ions from the cathode under acidic conditions. This diffusion induces the coalescence of neighboring ZnO NPs, forming defect-passivated, long-range ZnO crystals. When used as the electron transport layer in QLEDs, recrystallized ZnO NPs enhance the external quantum efficiency from 17.2% to 33.7% compared with devices with conventional ZnO electron transport layers. These findings offer valuable insights into the development of charge transport materials for high-performance optoelectronic devices.

DOI: 10.1038/s41377-025-01867-1

Source: https://www.nature.com/articles/s41377-025-01867-1