Origin of Positive Aging in Quantum-Dot Light-Emitting Diodes.

ABSTRACT: The phenomenon of positive aging, i.e., efficiency increased with time, is observed in quantum-dot light-emitting diodes (QLEDs). For example, the external quantum efficiency (EQE) of blue QLEDs is significantly improved from 4.93% to 12.97% after storage for 8 d. The origin of such positive aging is thoroughly investigated. The finding indicates that the interfacial reaction between Al cathode and ZnMgO electron transport layer accounts for such improvement. During shelf-aging, the Al slowly reacts with the oxygen from ZnMgO, and consequently, leads to the formation of AlO _x and the production of oxygen vacancies in ZnMgO. The AlO _x interlayer reduces the electron injection barrier while the oxygen vacancies increase the conductivity of ZnMgO and, as a

SUBMITTER: Su Q 

PROVIDER: S-EPMC6193172 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature