Structural, optical and electronic properties of La-doped ZnO thin films: Experimental study and DFT calculations

In this work, we investigated the electronic, optical and structural properties of Lanthanum-doped ZnO (LZO) for different concentrations of Lanthanum using experimental preparations by the spin-coating method of sol precursor on glass substrates and Full Potential Linearized Enhanced Plane Wave Method (FP-LAPW), based on the Density Functional Theory (DFT) and Boltzmann's Transport Theory by using the Tran-Blaha Modified Becke-Johnson approximation (TB-mBJ). As a valuable tool for simulating and designing materials, DFT methods have made great strides in the field of materials science. The XRD, SEM and UV–Vis–NIR spectrophotometry were used to obtain structural, morphological and optical properties of the deposited films, respectively. The experimental results indicate a wide band gap of 3.17 eV and show that polycrystalline thin films with a hexagonal wurtzite structure were grown. The optical properties indicate that the films transmittance in the visible region is more than 85% and increases with the concentration of La, as well as the absorption coefficient. By the approximation used, the value of this gap was underestimated. The high static value of the refractive index and the low reflectivity were observed in the visible region.