Study on synthesis, growth mechanism, and optoelectronic properties of SnZrS3 semiconductor

SnZrS3 is a promising but underexplored chalcogenide semiconductor for optoelectronic applications. Herein, we report a two-step solid-state route in which a highly crystalline ZrS2 intermediate, pre-formed in the first step, reacts with SnS at 600 °C in the second step. Systematic optimization identifies 600 °C, 6 h, and a 1:1 precursor ratio as the optimal conditions. The growth mechanism is elucidated as a template-induced topological transformation in which the morphology of the final SnZrS3 product is inherited from the ZrS2 precursor. DFT calculations reveal an indirect band gap of 1.08 eV, with the valence band edge dominated by S 3p states and the conduction band edge contributed by Zr 4d and Sn 5p states. UV–Vis spectroscopy gives an experimental optical band gap of 1.15 eV, in excellent agreement with the calculated optical band gap 1.14 eV. Raman spectroscopy combined with DFPT calculations identifies the characteristic Ag modes at 158.6 and 330.8 cm-1, assigned to in-plane Sn–S and Zr–S stretching vibrations. These results establish a controllable synthesis route and provide a combined experimental and theoretical understanding of SnZrS3 for photovoltaic and optoelectronic applications.