Hole transport in Mg-doped GaN epilayers grown by metalorganic chemical vapor deposition

A two-band model involving the heavy- and light-hole bands was adopted to analyze the temperature-dependent Hall effect measured on Mg-doped p-type GaN epilayers. At 300 K, the hole concentration was determined to be nearly twice the Hall concentration estimated from the measured Hall coefficient, meanwhile the Hall mobility of heavy hole turned out to be only half of the measured one. It is shown that the scattering by space charge and acoustic deformation potential is anomalously enhanced in Mg-doped GaN, and that the light hole affects conspicuously the observed transport parameters.