Influence of the particle size of CaCO₃ coating layer on the efficiency enhancement of SnO₂-based dye sensitized solar cells
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Date
2013
Authors
Siriwardena, E. K. D. H. D.
Journal Title
Journal ISSN
Volume Title
Publisher
University of Peradeniya
Abstract
Dye sensitized solar cells (DSSCs) have received much attention in the recent past over conventional silicon solar cells due to their low cost and easy fabrication. Even though Ti0₂ is considered to be the best high band gap semiconductor for DSSC, other materials such as ZnO and Sn0₂ having similar band gap positions and higher electron mobilities are under investigation. Sn0₂-based DSSCs show low photovoltaic performance due to higher recombination rates. However, there have been various attempts to reduce recombination in this system in order to harness its other positive electronic properties to achieve higher DSSC efficiencies. One such method is to use a very thing insulating CaC0₃ coating layer on Sn0₂ nanoparticles. This study is focused on the effect of particle size (diameter of the spherical particle) of the CaC0₃ coating layer on the efficiency enhancement of Sn0₂/CaC0₃ composite DSSCs. CaC0₃ nanoparticles of 15 nm, 20 nm, 30 nm and 50 nm were prepared in the laboratory and used in the coating layer to fabricate Sn0₂-based DSSCs while keeping Sn0₂ :CaC0₃ molar ratio at 50:1 in order to control the thickness of the coating layer and to change the effective surface area. A maximum photoconversion efficiency of 6.13% was obtained for 15 nm CaC0₃ nanoparticles. There is clear experimental evidence that the increase in efficiency enhancement is due to the increase in the overall surface area for smaller particle sizes of CaC0₃.
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Keywords
Dye-sensitized solar cells , Calcium carbonate , DSSCs