Decoupling the Conductivity–Fluorescence Tradeoff of SnO2 Nanocrystals for Efficient and Stable Quantum Dot Light‐Emitting Diodes
Year: 2024
Type: article
Abstract: Electron‐transporting layers (ETLs) assembled from SnO2 nanocrystals show promise in addressing the stability issues faced by solution‐processed quantum dot light‐emitting diodes (QLEDs). However, the electrical conductivity of SnO2 nanocrystals bottlenecks QLED performance, and efforts to achieve effective n‐type doping are constrained by dopant availability and charge‐induced exciton quenching. In response, Sb‐doped SnO2 nanocrystals with doping concentrations less than 1 mol% are explored, a range overlooked in previous research, and the ETL is designed accordingly. Comprehensive characterizations reveal that 0.45 mol% Sb doping transitions the electrical conduction from trap‐limited to trap‐free space‐charge‐limited, and 0.84 mol% doping results in Ohmic conduction, along with a 100‐fold conductivity enhancement. Meanwhile, trap‐filling mitigates the fluorescence quenching of the colloidal quantum dots, with significant increases only observed when doping concentrations exceed 0.45 mol%. Drawing inspiration from these findings, a SnO2 ETL with gradient Sb doping levels for QLEDs to decouple the conductivity–fluorescence tradeoff is developed. Consequently, this ZnO‐free QLED significantly outperforms comparable devices, achieving a luminance of 2.8 × 105 cd m−2, an external quantum efficiency of 18.3%, and a T95 operational lifetime of 4320 h at 1000 cd m−2, all while showing no signs of positive aging.
Source: Laser & Photonics Review
Authors: Xueqing Xia, Xingtong Chen, Jiachen Xie, Xinrui Li, Song Chen
Institution: Soochow University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
Awards: G2296154835, G6767289561
OpenAlex ID: W4405338304