The doping process of p-type GaN films

The formation of p-type GaN film is a key technology in developing optoelectronic devices. P-type doping (concentration∼1017 cm−3) has been achieved in grown GaN by metalorganic chemical vapor deposition (MOCVD) with Mg (CP2Mg) doping. The Hall measurement results indicate that Mg diffused GaN films also have p-type conductivity with carrier concentration about 1017 cm−3 and a mobility of 10 cm2 V−1 s−1. For the as-grown Mg-doped GaN, the room temperature photoluminescence (PL) spectra show a blue emission peak around 420–450 nm, and the spectral peak depends on the carrier concentrations. For Mg-diffused GaN, the PL spectra shows only a broad violet emission for samples diffused at 900–1100°C.