Tuning the Optical, Electrical, and Optoelectronic Properties of CuO Thin Films Fabricated by Facile SILAR Dip‐Coating Technique for Photosensing Applications

Abstract

CuO thin films deposited using SILAR coating technique with various dip-cycles. The prepared thin films were characterized to elucidate the structural and morphological features using analytical techniques such as XRD and SEM, respectively. It was found that along with the thickness of CuO films, the crystallinity and morphology of the deposited films have changed appreciably. The optical, electrical, and photosensing properties were also studied for deposited films. The optical and electrical properties for the thin film prepared with 100 dip-cycles were found best as compared to 50, 75, 125 dip-cycles, this may be due to improved crystallinity and uniform distribution of nanoclusters over the substrate. From the UV absorption studies, it was found that the CuO-100 thin-film has the highest absorption and a low bandgap of 1.67 eV. Also, the CuO with 100 dip sample exhibits a minimum resistivity of 2.98 × 102 Ω cm that leads to a higher carrier concentration of 4.63 × 1013 cm−3 and mobility of 4.53 cm2V−1 s−1. The I–V characteristics of all the deposited CuO samples were investigated and the CuO-100 dip cycle thin film is found to have a lower ideality factor of 5.4. Additionally, the Cu-100 thin film reveals a high responsivity and external quantum efficiency values of 1.67 × 10−1 A/W and 54%, respectively. Thus, in the SILAR dip-coating technique, the dipping cycles influence the CuO formation as well as their properties.