Solution-Processed Zn-Doped In2S3 Electron Transport Layers for Quantum Dot Light-Emitting Diodes
Youhua Zuo1, Chen Lin1, Xuecong Shen1
1State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures; Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials; Guangxi Key Laboratory of Advanced Rare Earth Materials; School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Abstract:
Wide-bandgap ZnO, SnO2 and TiO2 nanoparticles have been commonly employed as electron transport layers (ETLs) to fabricate quantum dot light-emitting diodes (QLEDs) due to their excellent optoelectronic properties. Conversely, the use of metal sulfide nanoparticles as ETLs in QLEDs remains unreported to date. In this work, we demonstrate, for the first time, the application of bandgap-tunable and mobility-adjustable Zn-doped In2S3 thin films as ETLs in QLEDs. Benefiting from their appropriate electron mobility and high electrical conductivity, these metal sulfide ETLs effectively enhance charge transport efficiency in the devices. Consequently, the red inverted QLEDs based on the 20% Zn-doped In2S3 ETL achieve outstanding optoelectronic performance, with a maximum external quantum efficiency (EQE) of 12.97%, a peak current efficiency of 17.86 cd A-1 and a maximum luminance of 89,100 cd m-2. These results indicate that Zn-doped In2S3 is a promising ETL candidate for high-performance QLEDs and establish a new design concept for developing high-performance QLEDs based on metal sulfide ETLs.
