文摘
A dual hole injection layer (d-HIL) composed of graphene oxide (GO) and transition metal oxide MoO3 is constructed and proven to be effectively promotes the radiance and external quantum efficiency (EQE) of ultraviolet organic light-emitting diode (UV OLED). The device with d-HIL behaves a maximum radiance of 4.7 mW/cm2 at 237.5 mA/cm2 and EQE of 1.36% at 3.75 mA/cm2, which have been enhanced by 27% and 19%, respectively, in comparison with the coun- terpart using conventional MoO3single HIL. The ultraviolet photoelectron spectroscopy elucidates that GO/MoO3 modification to the greatest extent enhances work function. The current-voltage characteristics and impedance spectroscopy of Hole-only devices clarify that GO/MoO3 d-HIL considerably promotes hole injection capacity. Our results indicate that the d-HIL of GO/MoO3 paves a way for constructing efficient UV OLED.