Structural and optical properties of Er-doped AlN

Based on first-principles calculations, we have studied the crystal, electronic structure and optical properties in both wurtzite and zinc blend structure of AlN doped with rare-earth element Er. The calculations indicate that the lattice parameters increase after doping showing the distortion of the crystal structure and its density of states is obviously asymmetric indicating the sample is magnetism. The static dielectric constant epsilon(1)(0) of doped systems are increasing compare with pure AlN and the value of zinc blend structure Al0.75Er0.25N is biggest than that of other structures. Dielectric imaginary part epsilon(2)() and absorption coefficient I() both show red shift and the absorption enhance in visible region after doping.