Study of Influence of Sulfurisation Temperature on the Resistivity and Surface Morphology of Thermally Evaporated Cuals2 Thin Films

Abstract

CuAlS2 thin film samples of equal thicknesses were deposited on corning glass substrate at the same substrate temperature by thermal evaporation method. Samples were subsequently sulfurised at different sulfurisation temperatures. Electrical characterization was performed by using Keithley four point probe meter and morphological characterization was carried out by employing Evoma-10 Scanning electron microscope. It was observed that resistivity decreases as sulfurisation temperature increases. The lowest resistivity was recorded at an elevated sulfurisation temperature and this is related to increase of carriers concentration with increase in sulfurisation temperature. Low electrical resistivity and high carriers concentration are essential components widely used in fabrication of various optoelectronic devices and solar cells. The scanning electron microscopy (SEM) micrographs of the films revealed that size of the crystallite increase with increase in sulfurisation temperature. Increase in crystallite size implies increase in crystallinity of films which also prove the quality of the films.