Can tweaking the composition of materials alter their light absorption properties? This research explores how doping titanium dioxide with sulfur affects its band gap, revealing insights for advanced solar energy applications. This paper reports the synthesis of sulfur-doped titanium dioxide (TiO2) through oxidation annealing of titanium disulfide (TiS2). The resulting TiO2 exhibits a narrowed band gap, with S atoms occupying O-atom sites and forming Ti–S bonds. Theoretical analyses confirm that mixing of S 3p states with the valence band contributes to this band gap narrowing. The band gap narrowing of titanium dioxide has implications for lower-energy region absorption. It also opens up the possibility of other applications in solar technology.
Published in _Applied Physics Letters_, this research is highly relevant due to the journal’s emphasis on experimental physics and its applications in materials science. The study's findings regarding sulfur doping and band gap narrowing contribute to the understanding of semiconductor properties and their potential for technological advancements.