Activation energy and electrical activity of Mg in Mg-doped InxGa1-xN (x < 0.2)

We investigated the electrical properties of Mg-doped InGaN with an In mole fraction of less than 0.2 grown by metaloganic vapor phase epitaxy. We obtained p-type InGaN with a hole concentration above 10(18) cm(-3) at room temperature. The hole concentrations of Mg-doped In0.04Ga0.96N and In0.14Ga0.86N were 1.2 x 10(18) and 6.7 x 10(18) cm-3, respectively, while that of Mg-doped GaN was 3.0 x 10(17) cm(-3) with the same Mg doping concentration. The activation energy of Mg in InGaN, calculated from the temperature dependence of the hole concentration, decreases with the increase in the In mole fraction. Furthermore, the electrical activity of Mg in InGaN increases with the In mole fraction. As a result, higher hole concentrations were obtained at room temperature for Mg-doped InxGa1-xN (x < 0.2) with higher In mole fractions.