Low activation energy of Mg-doped InxGa1−xN (x∼0.4) and self-compensation modelling

p-InGaN epitaxial layer is crucially important for advanced electronic and optoelectronic devices. The activation energy (E_A) of Mg-acceptor, universally accepted p-type dopant, and hole concentration (p) of Mg-doped In_xGa_1-xN alloys (x~0.4) have been investigated herein. The E_A has been calculated using an equation almost fitted with experimental data available in literatures in which E_A decreases with the increase in In content (x) in In_xGa_1-xN. The observed EA in Mg doped In_0.4Ga_0.6N alloys is about 41 meV which is few times smaller than Mg doped GaN, widely used active p-layer from III-nitride. The increased carrier concentration (p) due to increasing In content is near about 9.7×10¹⁸ cm^-3 for x~0.4. The hole concentration starts to decrease at around the Mg concentration of 4.5×10¹⁹ cm^-3. These results indicate that self-compensation occurs in Mg-doped InGaN at higher-doping levels.