Effect of annealing on the structural properties of thermal evaporated CdIn2Te4/CdS thin film solar cells

In this study, a thermal evaporation technique and the effect of annealing on the structural properties of CdIn2Te4/CdS thin film solar cells were investigated. Thin film solar cells were deposited onto an indium tin oxide (ITO)-coated glass substrate using a thermal evaporation technique. The nitrogen atmosphere was 400 °C for 1 h of annealing. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDAX) analysis were performed on the solar cells. XRD analysis revealed two peaks (2θ = 27.2° and 33.6°). We observed increased peak severity but identical peak position in the annealed films. The X-ray diffraction patterns of the annealed and as-deposited solar cells’ preferred orientations in nature have been detected as (200) and (202), respectively. Crystallite size (D), inter-planar distance (d), and lattice constant (a) values were calculated for the thin film solar cells using the XRD data. When examining the EDAX analysis and element placement, we detected only CdIn2Te4 in the absorber layer and only CdS atoms in the window layer, but no impurity atoms in the structure. We also observed an increase in surface roughness of the annealed films in SEM images. The I–V characteristics show that the current is increased for annealed thin films solar cells.