Dassanayake, M. S.Karunarathne, A. K.Bandara, K. M. P. S.Bandara, T. M. W. J.2024-10-292024-10-292024-11-01Proceedings of the Postgraduate Institute of Science Research Congress (RESCON) - 2024, University of Peradeniya, P 1883051-4622https://ir.lib.pdn.ac.lk/handle/20.500.14444/2776Quantum dots (QDs) are semiconductor nanoparticles exhibiting unique optical and electrical properties due to quantum confinement, which differ from those of the bulk material because of their nano-size. Quantum dot-sensitized solar cells (QDSSCs) belong to the third generation of solar cells and incorporate QDs into the photoanode, acting as photosensitizers. The structure of a QDSSC consists of a photoanode, an electrolyte and a counter electrode. The present study is focused on the preparation of quasi-solid state QDSSC with new polysulfide gel polymer electrolytes. A polysulfide electrolyte is used because it is more suitable for Cadmium Sulfide (CdS) quantum dot solar cells compared to other common electrolytes like I⁻/I³⁻. In this study, multilayer Titanium Dioxide (TiO₂) photoanodes were fabricated using spin coating and doctor blade methods on Fluorine-doped Tin Oxide substrates. TiO₂ acts as the nanostructured metal oxide semiconductor layer, which mediates the electron transportation through the photoanode. CdS QDs, which are the light-harvesting species, were gradually grown on the mesoporous TiO₂ films using Successive Ionic Layer Adsorption and Reaction (SILAR) method. The room temperature conductivity of gel polymer electrolyte was 20.78 Ms/cm, and it increases with temperature. The cell performances were investigated by applying 10 SILAR cycles of CdS to the photoanode. In this study, 2-layer and 4-layer TiO₂ photoanodes were used with polysulfide gel electrolyte along with a Platinum counter electrode. The maximum efficiency of 0.76% was observed in CdS QDs-embedded solar cells with a 4-layer TiO₂ photoanode, with an open circuit voltage (Voc) of 0.49 V and a short circuit current density (Jsc) of 3.71 mA/cm². The maximum efficiency of the cells fabricated with a 2-layer TiO₂ photoanode was 0.71% together with Voc of 0.40 V and Jsc of 4.70 mA/cm². The higher efficiency of cells with a 4-layer TiO₂ photoanode demonstrates that increasing the number of TiO₂ layers enhances solar cell efficiency.enCadmium Sulfide Quantum dotsGel polymer electrolytesPolysulfide electrolytesSolar cellArticle