Fabrication and characterization of 395Â nm ultraviolet GaN light-emitting diodes

In this article, we demonstrated the fabrication and characterization of 395 nm GaN ultraviolet light-emitting diodes grown on patterned sapphire substrates. The current confining aperture is designed as 45, 55, 65, 75 and 85 μm. The indium tin oxide (ITO) was used as a current spreading layer. Use the metals of nickel and gold to form ohmic contact with P-AlGaN layer prior to dry etching. The 45-μm-diameter LED exhibits a 3-dB modulation bandwidth of 134 MHz at 50 mA and a light output power density of 1.2 mW (78 W/cm2) at 30 mA. In addition, the 3-dB frequency bandwidth is proportional to the square root of the injected current density.