Theoretical DFT and experimental investigation of the effect of Co doping in electrochemically deposited ZnSe films

Abstract

In this study, we examine the impact of introducing cobalt doping on the morphological, structural, optical, and electronic properties of ZnSe thin films produced by electrodeposition at room temperature. Characterization techniques, including X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and UV–Vis–NIR spectroscopy, were employed to analyze structural, morphological, and optical features. The developed films display a consistent and even distribution of grains with a cubic structure, showcasing a preferred orientation along the (111) axis. The calculated crystal size was estimated to be around 80 nm. The elemental composition of the film aligns with the synthesized deposition of elements. The introduction of cobalt resulted in enhanced optical properties and reduced energy bandgaps in the films. Concurrently, theoretical studies using the FP-LAPW approach in density functional theory were conducted, focusing on structural, electronic, and optical properties of cobalt-doped ZnSe at different concentrations (2 %, 4 %, 6 %). Theoretical findings demonstrated a substantial decrease in the bandgap, aligning well with the experimentally determined value of 2.72 eV. This coherence between theoretical predictions and experimental observations highlights the effectiveness of cobalt doping in influencing the optical characteristics of ZnSe thin films.