DOPING PROPERTIES OF AMPHOTERIC C, SI, AND GE IMPURITIES IN GAN AND ALN

Electronic structure of substitutional group-IV impurities C, Si, and Ge in hexagonal GaN and AIN were studied by quantum molecular dynamics . C-N is a very shallow acceptor, and thus a promising p-type dopant. Both Si and Ge are excellent donors in GaN. However, in AlGaN alloys t he DX configurations are stable for a sufficiently high Al content, wh ich quenches the doping efficiency. Electronic structure of nearest-ne ighbor X(cation)-X(N) pairs is also discussed.