Colloidal Synthesis of Ternary Copper Halide Nanocrystals for High-Efficiency Deep-Blue Light-Emitting Diodes with a Half-Lifetime above 100 h

Lintao Wang; Zhifeng Shi; Zhuangzhuang Ma; Dongwen Yang; Fei Zhang; Xinzhen Ji; Meng Wang; Xu Chen; Guangren Na; Shu Chen; Di Wu; Yu Zhang; Xinjian Li; Lijun Zhang; Chongxin Shan

doi:10.1021/acs.nanolett.0c00513

Colloidal Synthesis of Ternary Copper Halide Nanocrystals for High-Efficiency Deep-Blue Light-Emitting Diodes with a Half-Lifetime above 100 h

Nano Lett. 2020 May 13;20(5):3568-3576. doi: 10.1021/acs.nanolett.0c00513. Epub 2020 Apr 7.

Authors

Lintao Wang¹, Zhifeng Shi¹, Zhuangzhuang Ma¹, Dongwen Yang¹, Fei Zhang¹, Xinzhen Ji¹, Meng Wang¹, Xu Chen¹, Guangren Na², Shu Chen¹, Di Wu¹, Yu Zhang³, Xinjian Li¹, Lijun Zhang², Chongxin Shan¹

Affiliations

¹ Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China.
² State Key Laboratory on Integrated Optoelectronics, Key Laboratory of Automobile Materials of MOE, and College of Materials Science and Engineering, Jilin University, Changchun 130012, China.
³ State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Qianjin Street 2699, Changchun 130012, China.

PMID: 32243171
DOI: 10.1021/acs.nanolett.0c00513

Abstract

Currently, the blue perovskite light-emitting diodes (PeLEDs) suffer from a compromise in lead toxicity and poor operation stability, and most previous studies have struggled to meet the crucial blue NTSC standard. In this study, electrically driven deep-blue LEDs (∼445 nm) based on zero-dimensional (0D) Cs₃Cu₂I₅ nanocrystals (NCs) were demonstrated with the color coordinates of (0.16, 0.07) and a high external quantum efficiency of ∼1.12%, comparable with the best-performing blue LEDs based on lead-halide perovskites. Encouraged by the remarkable stability of Cs₃Cu₂I₅ NCs against heat and environmental oxygen/moisture, the proposed device was operated in a continuous current mode for 170 h, producing a record half-lifetime of ∼108 h. The device stability was further verified by an aggressive thermal cycling test (300-360-300 K) and a 35-day storage test. Together with the eco-friendly features and facile colloidal synthesis technique, the 0D Cs₃Cu₂I₅ NCs can be therefore regarded as a promising candidate for deep-blue LEDs applications.

Keywords: Cs3Cu2I5 nanocrystals; deep-blue; light-emitting diodes; self-trapped excitons; stability.