Triphenylamine-based organic dye containing the diphenylvinyl and rhodanine-3-acetic acid moieties for efficient dye-sensitized solar cells

In this paper, we report on the synthesis, characterization of a new triphenylamine (TPA) derivative (TPAR14) with a “secondary electron transferring” structure as well as its application to dye-sensitized solar cells (DSCs). The introduction of diphenylvinyl to the adjacent phenyl ring of the TPA core could not only increase the extinction coefficient and λ_max by the extension of π-conjugation, but also form three-dimensional obstacle for dye aggregation and triiodide that is in favor of higher open-circuit photovoltage (V_oc). An overall light-to-electricity conversion efficiency of 6.27% is obtained for the DSC with the as-synthesized dye under AM 1.5 irradiation (100 mW cm⁻²), which is the highest value among the TPA-rhodanine-3-acetic acid-based DSCs. The long-term stability test of TPAR14 under heat shows its character of high stability. The present work indicates that the as-synthesized TPAR14 is promising in the application of DSCs.