Mg acceptor level in InN epilayers probed by photoluminescence

Abstract

Mg-doped InN epilayers were grown on sapphire substrates by metal organic chemical vapor deposition. Effects of Mg concentration on the photoluminescence (PL) emission properties have been investigated. An emission line at ∼0.76eV, which was absent in undoped InN epilayers and was about 60meV below the band-to-band emission peak at ∼0.82eV, was observed to be the dominant emission in Mg-doped InN epilayers. The PL spectral peak position and the temperature dependent emission intensity corroborated each other and suggested that the Mg acceptor level in InN is about 60meV above the valance band maximum.