Optimization of electronic and optical properties of transition metal doped ZnO By DFT+U method and supported by experimental findings

First principal calculations were performed to investigate the structural, electronic, and optical properties of metal doped ZnO (M-ZnO), where M = Ru, Mo, Pt, Mn, Cr, Nb, Fe and Pd. For our calculations we used the generalized gradient approximation plane-wave pseudopotential with the incorporation of Hubbard U established on density functional theory. The computational calculations had a fixed dopant concentration of 6.25 wt% and among the studied materials the most suitable material was based on the lattice stability, band gap reduction and shift towards the visible region of the spectrum. Cr doped ZnO is found to be the most favorable material based on the computational study, this is experimentally synthesized via sol-gel method in multiple concentrations of 5 wt% and 10 wt%. The experimental results of the material are also found consistent with the computational study as evident by observation of the band gap reduction and a red shift. So, the Cr doped ZnO is found to be the most suitable material among the studied as it would have augmented photocatalytic activity, which is established on our density functional theory calculations and supported by experimental findings.