Optical and Electrical Characteristics of CO2-Laser-Treated Mg-Doped GaN Film

This work investigates the optical and electrical characteristics of CO2-laser annealed Mg-doped GaN films to activate Mg-doped p-type GaN films. Results obtained from the CO2 laser annealing investigation were similar to those of thermal annealing or low energy electron beam irradiation (LEEBI) treatment to activate the Mg-doped p-GaN films. The room-temperature photoluminescence (PL) intensity of the blue emission of the Mg-doped GaN film after 10 W laser annealing was approximately ten times stronger than that of the as-grown film. The resistivity of the Mg-doped GaN film decreased from 105 Ω·cm to 2–3 Ω·cm as the laser annealing power rose above 6 W. The hole concentration of Mg-doped GaN film was approximately 1×1017 cm-3 when the laser annealing power was 7.5 W.