title: Enhanced hole injection in phosphorescent organic light-emitting diodes by thermally evaporating a thin indium trichloride layer.
abstract: An ultrathin layer of indium trichloride (InCl(3)) is thermally evaporated on the indium tin oxide (ITO) anode to enhance the hole injection in simplified phosphorescent organic light-emitting diodes (PHOLEDs). Comparing with the device with ultraviolet (UV)-ozone treatment, the device modified by InCl(3) exhibits a maximum current efficiency of 82.2 cd/A measured at about 2000 cd/cm(2) and 36% improvement in power efficiency measured at 20 mA/cm(2). More importantly, more than three times improvement in half lifetime estimated at an initial luminance of 1000 cd/cm(2) is achieved. The investigations using ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and the bias- and temperature-dependent current density-voltage characteristics in the related hole-dominated devices have revealed that the improved device performance is mainly attributed to the enhanced hole injection resulting from the lowered hole injection barrier height in the InCl(3)-modified devices.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China.
authors.forename: Chun-Hong
authors.initials: CH
authors.lastname: Gao
authors.forename: Shi-Duan
authors.initials: SD
authors.lastname: Cai
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.forename: Dong-Ying
authors.initials: DY
authors.lastname: Zhou
authors.forename: Zhao-Kui
authors.initials: ZK
authors.lastname: Wang
authors.forename: Liang-Sheng
authors.initials: LS
authors.lastname: Liao