Studies on the Synthesis of New Dyes for Dye-sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSCs) have received much attention because of their low fabrication cost and relatively high power conversion efficiency. Among three components of DSCs, a dye is an essential factor for realizing highly efficient DSCs. Here, we present synthesis and DSC performance of new organic dyes. In the first part, we present the synthesis of three metal-free organic dyes consisting of triphenylamine, carbazole as an electron donor and cyanoacrylic acid as an anchoring group, which are linked by thiophene and benzothiadiazole. The best power conversion efficiency was achieved by H13 dye which composed of hexyl thiophene as a π-bridge. The best efficiency, 6.33%, was obtained with H13 and 10 mM CDCA, with a Voc of 0.71 V, a Jsc of 12.69 mA∙cm−2, and a FF of 0.71. In the second part, we present our attempts towards the development of squaraine based dyes consisting of phenanthroimidazole and thiophene-bridge, which utilize the Förster resonance energy transfer within a dye for achieving better power conversion efficiency.