Interfacial electronic structure between a W-doped In2O3 transparent electrode and a V2O5 hole injection layer for
Su Been Heo1, Jong Hun Yu1, Minju Kim2
1Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University 1732 Deogyeong-daero, Giheung-gu Yongin Gyeonggi-do 17104 Republic of Korea junkang@khu.ac.kr +82-31-201-3324.
Abstract:
The interfacial electronic structure between a W-doped In2O3 (IWO) transparent electrode and a V2O5 hole injection layer (HIL) has been investigated using ultraviolet photoelectron spectroscopy for high-performance and inorganic quantum-dot light-emitting diodes (QLEDs). Based on the interfacial electronic structure measurements, we found gap states in a V2O5 HIL at 1.0 eV below the Fermi level. Holes can be efficiently injected from the IWO electrode into poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(4-sec-butylphenyl)diphenylamine)] (TFB) through the gap states of V2O5, which was confirmed by the hole injection characteristics of a hole-only device. Therefore, conventional normal-structured QLEDs were fabricated on a glass substrate with the IWO transparent electrode and V2O5 HIL. The maximum luminance of the device was measured as 9443.5 cd m-2. Our result suggests that the IWO electrode and V2O5 HIL are a good combination for developing high-performance and inorganic QLEDs.
