Balanced charge transport and enhanced performance of blue quantum dot light-emitting diodes via electron transport layer doping

Yue Yang; Liang Su; Nannan Feng; Anqi Liu; Xiaoxue Xing; Min Lu; William W Yu

doi:10.1088/1361-6528/abff8c

Balanced charge transport and enhanced performance of blue quantum dot light-emitting diodes via electron transport layer doping

Nanotechnology. 2021 May 25;32(33). doi: 10.1088/1361-6528/abff8c.

Authors

Yue Yang¹, Liang Su¹, Nannan Feng¹, Anqi Liu¹, Xiaoxue Xing², Min Lu¹, William W Yu³

Affiliations

¹ State Key Laboratory of Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun 130012, People's Republic of China.
² College of Electronic Information Engineering, Changchun University, Changchun 130022, People's Republic of China.
³ Department of Chemistry and Physics, Louisiana State University, Shreveport, LA 71115, United States of America.

PMID: 33971629
DOI: 10.1088/1361-6528/abff8c

Abstract

The unbalanced charge transport is always a key influencing factor on the device performance of quantum dot light-emitting diodes (QLEDs), particularly for the blue QLEDs due to their large optical band gap. Here, a method of electron transport layer (ETL) doping was developed to regulate the energy levels and the carrier mobility of the ETL, which resulted in more balanced charge injection, transport and recombination in the blue emitting CdZnS/ZnS core/shell QLEDs. Consequently, an enhanced performance of blue QLEDs was achieved by modulating the charge balance through ETL doping. The maximum external quantum efficiency and luminance was dramatically increased from 2.2% to 7.3% and from 3786 cd m^-2to 9108 cd m^-2, respectively. The results illustrate that charge transport layer doping is a simple and effective strategy to regulate the charge injection barrier and carrier mobility of QLEDs.

Keywords: charge transport; light-emitting diodes; quantum dots.