Investigation of thermally induced surface composition and morphology variation of magnetron sputtered Sb<sub>2</sub>Se<sub>3</sub> absorber layer for thin film solar cells
Ayten Cantas
Abstract
Abstract One of the most promising semiconductor materials for the development of sustainable thin-film solar cell technology is antimony selenide (Sb 2 Se 3 ). Its excellent optical and electrical properties have drawn attention lately for potential application in thin-film solar cells. In this study, Sb 2 Se 3 films deposited using the direct current (DC) magnetron sputtering technique have been subjected to a post-annealing process without an extra selenium supply at temperatures between 150 and 450 °C. Without an extra selenium supply, the impact of post-annealing temperature on the surface composition as well as the physical properties of the fabricated films was investigated. The overall evaluations revealed that the post-annealing temperature is highly efficient in altering the physical properties of the Sb 2 Se 3 absorber thin films. We further observed that the post-annealing process improved the crystallization and the heat treatment temperature quite affected preferential orientation. The surface morphology of films exhibited structural deformation at high post-annealing temperatures (> 350 °C). According to optical and electrical characterizations, respectively, the optical energy gap and the resistivity of Sb 2 Se 3 films reduced with an increment in the post-annealing temperature. Based on the XPS result, the variation in temperature of post-annealing led to a change in the surface composition of the films. The findings on the growth of Sb 2 Se 3 thin films indicate the existence of an intermediate growth temperature that permits the growth of Sb 2 Se 3 films to be optimized. The study’s conclusions can serve as a guide to the growth of Sb 2 Se 3 thin films with the desired crystallinity, surface morphology, and composition for thin film solar cell applications.