Optical Quenching of Persistent Photoconductivity in GaN Epilayer
GaN外延材料中持续光电导的光淬灭

Optical quenching of persistent photoconductivity (PPC) in n-type unintentional doped GaN and Si-doped GaN is investigated.Quenching extent of PPC in the former is much larger than that in the latter.After the quench light PPC is removed nearly no change happens in the former while the PPC decreases obviously in the later.When the quenching light is turned on again after a while,PPC is unchanging in the former while increases instead in the later.The origins of the PPC in unintentional doped and Si-doped GaN both are considered having relations with hole traps based on the experimental results.Hole trap model is used to explain the origin of PPC and its optical quenching in unintentional doped GaN.And the PPC of Si-doped GaN is regarded as the effect of both electron traps and hole traps,one of which is dominant at different stages of PPC.