DFT study of 3d transition metal-doping effect in wurtzite-ZnO for photovoltaic applications

摘要

Reduction in band gap of zinc oxide is the key requirement to enhance the photo conductivity of the material under visible light irradiation, which will helpful to fabricate high efficiency energy harvesting solar cell. Herein, 3d transition metal doped 2 × 2 × 2 supercell of wurtzite ZnO has been studied using full potential linearized augmented plane-wave (FP-LAPW) method within the DFT implemented in WIEN2k code. As a result of doping, many impurity levels have been observed in the band gap region of the pure ZnO, which are effectively reduce the band gap of the material. Total density of states (TDOS) plots reveal that the Fe, Ni, Co-doped ZnO show both p-type and n-type conductivity of the samples, whereas Cu-doped ZnO shows only p-type conductivity as all the impurity levels lie below the Fermi level when Cu dopant is used. Hence the present study is not only important for the basic understanding of the 3d transition metal doping effect ZnO but also has a tremendous application in designing high efficiency energy harvesting solar cell.