Bandgap Bowing Parameters Of Iii-Nitrides Semiconductors Alloys

We report on a theoretical investigation of energy band gaps of III-nitrides, InN, GaN, AlN and their alloys, InxGa1-xN, InxAl1-xN and AlxGa1-xN. Our theoretical framework is based on a DFT fullpotential linearized augmented plane wave method within both GGA and LDA exchangecorrelation functional. Tran Blaha modified Becke-Johnson exchange potential was also invoked to accurately provide band gaps. We find strong nonlinear compositional dependence of In-containing alloys band gaps, in contrast to AlxGa1-xN which is nonlinear compositional dependence of Al-containing alloys band gaps is smaller. The reported bowing parameters for both functionals are; InxAl1-xN- 4.5 eV, InxGa1-xN- 1.8 eV while; AlxGa1-xN- 0.8 eV is weaker. Our findings, in particular for the LDA, are in close agreement to the major experimental and theoretical data reported so far.