Effect of substituents moiety in organic sensitiser based on carbazole on the performance of nanostructure dye-sensitised solar cells

Abstract

Purpose – The purpose of this paper is to prepare new organic dyes and use them as sensitisers in dye-sensitised solar cells. These dyes were synthesised and purified and then characterised by analytical techniques. Spectrophotometric evaluations of the prepared dyes were carried out in solution and on a nano-anatase TiO2 substrate to assess the possible changes in the status of the dyes in different environments. Finally, the photovoltaic properties were investigated in dye-sensitised solar cells. Design/methodology/approach – So as to synthesise dyes, N-substituents carbazole were utilised as the fundamental electron donor group and cyanoacrylic acid or acrylic acid as electron acceptor anchoring groups. Purified dyes were dissolved in solution and coated on TiO2 substrate. Finally, dye-sensitised solar cells were fabricated to determine the photovoltaic behaviour and conversion efficiency of each individual dye. Findings – The results showed that the dyes form j-type aggregates on the nano TiO2. The oxidation potential of synthesised carbazole dyes is > 0.2 V vs Fc/Fc+; hence, their high performance in dye-sensitised solar cells. Dye 3 exhibited 2.11 per cent of conversion efficiency in comparison to 2.89 per cent for the identical cells with Dye 9 containing cyanoacrylic acid which acted as the best acceptor group. Practical implications – The novel dyes look as promising as highly light fast, efficient dyes for dye-sensitised solar cells. Social implications – Organic dye provides low cost and less hazardous materials for dye-sensitised solar cells. Originality/value – A series of new organic dyes were synthesised as sensitisers for dye-sensitised solar cells for the first time.