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.

Automated summary

This work analyzed the feasibility of using 'green' Ag- and Bi-based quantum dots (QDs) as sensitizers in quantum dot sensitized solar cells (QDSSCs) through theoretical and experimental approaches. The properties of different nanoclusters sensitizing the anatase-TiO2 (101) surface were investigated computationally, while the performance of the QDSSCs was validated experimentally. The results showed that post heat treatment improved the efficiency of Ag2S-Bi2S3 QDSSC, and UV-visible spectroscopy confirmed better absorption in the sample below 570 nm wavelength. However, the efficiency obtained was still low due to charge recombination.