AlGaN-based ultraviolet light-emitting diodes using fluorine-doped indium tin oxide electrodes

In this paper, improved electrical and optical properties of aluminum gallium nitride (AlGaN)-based ultraviolet light-emitting diodes using fluorine-doped indium tin oxide (F-ITO) electrodes are reported. F-doping was found to increase the work function as well as the energy bandgap of the ITO and, thereby, reduce the Shottky barrier height in contact with p-(Al)GaN. As a result, the optical transmittance increased from 79.7% to 86.9% at 380 nm, while the specific contact resistance decreased from 1.04 × 10−3 Ω·cm2 to 9.12 × 10−4 Ω·cm2 after F-doping, which led to an increase in the output power from 2.41 mW to 5.99 mW.