Computational and performance studies of Ag2S–Bi2S3 quantum dot-sensitised solar cells

In this work, theoretical and experimental techniques were employed to analyze the feasibility of ‘green’ Ag- and Bi-based QDs as sensitisers in QDSSC. In the computational approach, the geometrical structures and optoelectronic properties of anatase-TiO₂ (101) surface sensitised with Ag₂S, Bi₂S₃ and Ag₂S–Bi₂S₃ nanoclusters were investigated by means of density functional theory. In the experimental approach, the performances of the QDSSCs were validated. The properties of the QD-sensitised TiO₂ electrode were characterised with FESEM, TEM, EDS, and UV–visible spectroscopy. It was observed that Ag₂S–Bi₂S₃ QDSSC treated with post heat treatment exhibited better efficiency. UV–VIS spectroscopy result showed that the same sample had better absorption below the 570 nm wavelength. Efficiency obtained was at the low side due to charge recombination.