Temperature-Dependent Effects of FeS2 Thin Film Synthesized by Thermochemical Spraying: An Optical and Physicochemical Investigation

FeS2 pyrite films are used in a variety of applications including solar cells and, the potential scope for their utilization is increasing as their synthetic methods become more economical while maintaining or enhancing their high light absorption coefficients. The glass substrate temperature dependence on the formation of FeS2 pyrite films was investigated with respect to their optical and physicochemical properties. During the thermochemical spraying process the temperature was varied in the range of 190-290 °C. FeS2 nanocrystalline (40-70 nm) films, formed as a result of atmospheric spraying with glass substrate temperatures above 260 °C, were observed by SEM. Opto-electronic studies revealed that the nanocrystalline films had a direct band gap (1.3-1.6 eV) with a high light absorption coefficient (α > 7 × 104 cm−1 for λ < 1800 nm). Thus, this study offers an alternative to complicated methods for thin-film formation through spaying technology, for the synthesis of high-quality FeS2 pyrite films with potential application as high light-absorbing solar energy absorbers.