Highly Efficient SnO2/MgO Composite Film-Based Dye-Sensitized Solar Cells Sensitized with N719 and D358 Dyes

Abstract

SnO 2/ MgO composite film-based dye-sensitized solar cells (DSCs), sensitized with both N719 dye and metal-free D358 dye, employing [Formula: see text] redox couple-based liquid electrolyte, show superior performance to those sensitized with only D358 dye, and N719 dye. A significant improvement in the power conversion efficiency was attained by co-sensitizing the N719-based DSCs with metal-free D358 dye when compared to those obtained for DSCs with individual dyes. As confirmed by UV-visible absorption spectra, N719 dye adsorption is more prominent than that of D358 dye when sensitizing the SnO 2/ MgO composite film with the two dyes, D358 and N719. However, N719 and D358 dyes, when used alone, are prone to form aggregates on the SnO 2/ MgO composite film, when N719 dye is used together with D358, the latter effectively suppresses the aggregation of N719 dye on the SnO 2/ MgO composite film, thereby enhancing the power conversion efficiency of the DSCs. Hence, the corresponding power conversion efficiency of the SnO 2/ MgO composite film-based DSCs can be significantly improved by sensitizing with both N719 and D358 dyes. The reported power conversion efficiencies for the SnO 2/ MgO composite film-based DSCs, sensitized with, (a) D358 dye, (b) N719 dye, and (c) both N719 dye and D358 dye, are 6.37%, 7.43% and 8.60% respectively, under AM 1.5 illumination.