In our study, to optimize the electron-hole balance through controlling the electron transport layer (ETL) in the QD-LEDs, four materials (ZnO, ZnGaO, ZnMgO, and ZnGaMgO NPs) were synthesized and applied to the QD-LEDs as ETLs. By doping ZnO NPs with Ga, the electrons easily inject due to the increased Fermi level of ZnO NPs, and as Mg is further doped, the valence band maximum (VBM) of ZnO NPs deepens and blocks the holes more efficiently. Also, at the interface of QD/ETLs, Mg reduces non-radiative recombination by reducing oxygen vacancy defects on the surface of ZnO NPs. As a result, the maximum luminance (Lmax) and maximum luminance efficiency (LEmax) of QD-LEDs based on ZnGaMgO NPs reached 43440 cd m-2 and 15.4 cd A-1. These results increased by 34%, 10% and 27% for the Lmax and 450%, 88%, and 208% for the LEmax when compared with ZnO, ZnGaO, and ZnMgO NPs as ETLs.
|Number of pages||6|
|Publication status||Published - 2019|
Bibliographical noteFunding Information:
This work was supported by Korea Institute of Science and Technology (KIST) Institutional Program under Contract No. 2E28200 and South Africa/South Korea joint collaboration programmed managed by National Research Foundation, (Grant No. 2014K1A3A1A09063246/SKO15081792426)
© The Royal Society of Chemistry 2019.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)