Energy band gap and optical properties of non-stoichiometric InN-theory and experiment

The influence of antisite defects in InN is analyzed theoretically using a Linear Combination of Atomic Orbitals approach. The procedure used is validated by confirming the band gaps of common binary alloy semiconductor materials. InN with NIn and InN antisite defects are then analyzed and it is found that in the case of InN:NIn, the excess nitrogen acts as a donor species with its level resident in the conduction band. For InN:InN, it is shown that when there is a significant density of the excess indium present as the antisite defect, tunnel optical absorption should occur in the infrared at 0.2 eV.