Effect of Indium Ambient on Electrical Properties of Mg-Doped Al_xGa_1-xN

Mg-doped Al_xGa_1−xN epilayers were grown on AlN/sapphire templates by metal organic chemical vapor deposition (MOCVD) using an indium-assisted growth method. At room temperature, the resistivity of Mg-doped Al_0.43Ga_0.57N epilayer grown under indium (In) ambient is of the order of 10⁴ Ω⋅cm, while the resistivity of Mg−doped Al_0.43Ga_0.57N grown without In assistance is of the order of 10⁶ Ω⋅cm. The ultraviolet light−emitting diodes (UV-LEDs) using the In-assisted Mg-doped Al_0.43Ga_0.57N as the p−type layers were fabricated to verify the function of indium ambient. It is found that there are a lower turn-on voltage and a lower diode series resistance in the UV-LEDs fabricated with p-type Al_0.43Ga_0.57N layers grown under In-ambient.