Influence of various dithienoheterocycles as conjugated linker in Naphtho[2,3-d] [1,2,3]triazole-based organic dyes for dye-sensitized solar cells

Abstract

Three metal-free sensitizers HJL-1−HJL-3 based on the D-A′-π-A structure configuration incorporating electron-deficient naphtho[2,3-d] [1,2,3]triazole (NTz) as the conjugation spacer, various dithienoheterocycles as π linkers, were developed and used as the photosensitizers in dye-sensitized solar cells (DSSCs). The results indicate that all of the three dyes exhibit strong light-capturing ability in the visible region and obtain relatively high molar extinction coefficients (> 40000 M−1 cm−1) due to their strong charge transfer (CT) from donor to acceptor. Under standard global AM 1.5 G illumination, the DSSCs performance from these dyes exhibited conversion efficiencies ranging from 5.85% to 6.91%. After coadsorbed with CDCA, the DSSCs based on HJL-3 dyes gives 7.17%, which is about 95% of the N719-based standard cell.