Effect of potassium and erbium co-doping on the structural, electronic, optical and magnetic properties of zinc oxide

Abstract

Electronic and optical properties of (K, Er) co-doped ZnO were investigated by using FP-LAPW method with LSDA and LSDA+mBJ approximations. The lattice parameter of undoped ZnO was found in a good agreement with the experimental work; it was increased by doping ZnO with K and Er impurities. In this work, we showed the p-type doping ZnO from the band structure and density of states calculations. The band gap of ZnO was found to be decreased by co-doping with K and Er elements. We presented also the optical properties such as, the real and imaginary part of dielectric function, the refractive index and the absorption coefficient. This p-type appears by K and Er co-doping which occurs much shallow above the Fermi level. Er co-doping leads to the formation of magnetism in ZnO:K. ZnO has an absorption peak in UV region. Hence, (K, Er) co-doping leads to an optical peak in infrared region (IR) at about 1.75eV (equivalent to 775nm). The peak was found experimentally, and may improve the optical properties of ZnO-based devices.