Acceptor Levels due to a Complex Including the Nitrogen–Hydrogen Bond in GaAsN Films Grown by Chemical Beam Epitaxy

Abstract

The acceptor levels and their concentration in GaAsN films grown by the chemical beam epitaxy technique were investigated through detailed analysis of the temperature dependence of hole concentration. Two acceptor levels A1 and A2 were found, and their energy levels were fixed at 130 ±20 and 55 ±10 meV, respectively, from the valence band maximum. Both concentrations were on the order of 1017 cm-3 and compensated by the concentration of donor on the same order. The concentration of A1 had a linear relationship with the number of N–H bonds in films grown at the same growth temperature, while the slope decreased with growth temperature. These results strongly suggested that a complex defect including the N–H bond was the origin of the A1 acceptor level.