Phenethylammonium bromide interlayer for high-performance red quantum-dot light emitting diodes
Qiyin Chen1,2, Yun Hu3, Jie Lin3
1Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, China. gongsl@whu.edu.cn.
Abstract:
Interfacial modification is vital to boost the performance of colloidal quantum-dot light-emitting diodes (QLEDs). We introduce phenethylammonium bromide (PEABr) as an interlayer to reduce the trap states and exciton quenching at the interface between the emitting layer (EML) with CdSe/ZnS quantum-dots and the electron transport layer (ETL) with ZnMgO. The presence of PEABr separates the EML and the ETL and thus passivates the surface traps of ZnMgO. Moreover, the interfacial modification also alleviates electron injection, leading to more improved carrier injection balance. Consequently, the external quantum efficiency of the PEABr-based red QLED reached 27.6%, which outperformed those of the previously reported devices. Our results indicate that the halide ion salts are promising to balance charge carrier injection and reduce exciton quenching in the QLEDs.
