Isoelectronic doping of AlGaN alloys

Isoelectronic doping of Al x Ga 1-x N alloys with arsenic in films grown by molecular beam epitaxy has been investigated. In photoluminescence spectra of these Al x Ga 1-x N layers, there is a gradual increase of the band gap and a smaller progressive shift of the position of blue emission band to the higher energies as the Al content increases. To explain the change in the energy of the blue band in As-doped Al x Ga 1-x N alloys a model has been proposed, which predicts the shift in the blue band energy to be equal to the valence band offset from AlGaN to GaN. This prediction is consistent with the experimental results.