Analysis on the enhanced hole concentration in p‐type GaN grown by indium‐surfactant‐assisted Mg delta doping

Abstract

Abstract We have investigated the influence of indium surfactant on the hole‐concentration enhancement in Mg‐delta‐doped p‐type GaN grown at 920 °C. The hole concentration can be effectively enhanced from 7.8 × 10 17 cm −3 to 1.5 × 10 18 cm −3 when introducing the indium surfactant into the delta‐doping process. Analysis by secondary ion mass spectroscopy and low‐temperature photoluminescence results indicates that the increase of hole concentration is primarily contributed from the improved Mg incorporation and the suppressed N vacancy induced by the indium surfactant, while the contribution from unintentional C, Si, and O impurities and Ga‐vacancy‐related defects can be ruled out. On the other hand, it is shown that the acceptor activation energy, deduced from the temperature‐dependent photoluminescence, is decreased by indium surfactant, which is another factor accounting for the enhanced hole concentration.