Theoretical transport studies of p-type GaN/AlGaN modulation-doped heterostructures

We have calculated hole transfer and low-temperature mobilities in p-type GaN/AlGaN modulation-doped heterostructures. Although substantial p-type conduction is difficult to achieve in bulk nitrides, the strain-induced polarization field can greatly enhance the transfer of holes from relatively deep Mg acceptors in the AlGaN barrier into the GaN well. The calculations predict formation of a two-dimensional hole gas with densities greater than 1012 cm−2 and with low-temperature mobilities in excess of 104 cm2/V s.