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.