Full Electronic Band Structure Characterization of Al-Doped ZnO Nanocrystalline Films Through Simulation

The full electronic band structure of the Al doped ZnO films have been characterized using the TNL-FB™ (full band) simulator from Tech Next Lab. The bandgaps obtained through simulation studies were matched against the experimental bandgap and compared with the results obtained through DFT-based techniques. It was observed that the bandgap value at the Γ-valley increases with the increase in the Al dopant content from 0 at% to 5 at%. The extracted cut-off absorption wavelength was shifted to a shorter wavelength by increasing the Al content, and justifies the Burstein–Moss shift effect. In the present study, the dependency of the topology of the shape of the nanostructure films was taken care of through the lattice disorder effect. The influence of thickness and plane orientation on the various features has been carefully studied. The full electronic band structures of ZnO and AZO samples predicted that the bandgap value is strongly dependent on the internal structure parameter, u. The value of u is significantly affected by lattice disorder generated due to bond angle or length alteration dependent on the topology of the structure and impurity addition. Good agreement was found between the reported and experimental optical bandgap results.