Structural and electronic properties of ScxAl1−xN: First principles study

The structural and electronic properties of ScxAl1−xN ternary semiconductor alloys are investigated in the rocksalt, zinc blend and wurtzite structures using the full potential linear muffin tin orbitals (FP-LMTO) method. The local density approximation (LDA) was used for the exchange and correlation energy density functional. In particular, the lattice constant, bulk modulus and band gap energies of ScN and AlN compounds and their ternary alloys ScxAl1−xN are calculated in rocksalt, zinc blend and wurtzite structures and discussed. A linear relationship has obtained for equilibrium lattice constants versus Sc concentration for rocksalt and zinc blend structures. The band gap is decreased with the increasing of Sc concentration in the rocksalt phase. For ZB-ScxAl1−xN, the band gap is the largest one at x=0.25 and changes from indirect to direct when x is more than 0.25.