Dopant Effects on Defects in GaN Films Grown by Metal-OrganicChemical Vapor Deposition

The effects of dopants on the defects of GaN films were investigated by using different methods, such as wet etching of pits, x-ray diffraction and photoluminescence (PL). Three kinds of the samples were prepared with different dopants, that is, nominally undoped, Si-doped and Mg-doped GaN films. It was found that the lowest density of the etched pit was existed in the nominally undoped GaN, while the highest in the Mg-doped sample. The effects of the dopants on the etching pits were discussed.