Distinctive Extrinsic Atom Effects on the Structural, Optical, and Electronic Properties of Bi₂S_3-xSe_x Solid Solutions

For many decades, bulk Bi 2 S 3, a key low-bandgap metal chalcogenide semiconductor, has lagged behind in terms of potential applications due to its poor electrical properties. As such, controlling size extrinsic atom interactions in this material might emerge as a viable route to enhance its poor electrical properties. Here, we report the hydrothermal synthesis, structural characterization, and optoelectronic properties of Bi 2 S 3- x Se x solid solutions. Optical characterizations show a decrease in the bandgap of Bi 2 S 3 nanowires as a function of Se concentrations. Furthermore, ensemble electrical transport measurements suggest a pronounced increase in the electrical properties of Bi 2 S 3 nanowires upon Se incorporation. This study points to the importance of carefully controlling the stoichiometry and sizes in Bi 2 S 3 as a way to favorably tune its optoelectronic properties.