Rigid triarylamine-based efficient DSSC sensitizers with high molar extinction coefficients

Abstract

Five metal-free organic dyes (DIA1–DIA5) based on rigid triarylamine donors have been synthesized and their photophysical/electrochemical properties, theoretical calculations and dye-sensitized solar cell (DSSC) performances have been investigated. All the five dyes showed a high molar extinction coefficient (5.0 × 10⁴–8.1 × 10⁴ M⁻¹ cm⁻¹). Electrochemical measurement data indicates that the HOMO and LUMO energy levels can be conveniently tuned by alternating the π-spacer moiety. Among the five dyes, DIA3 showed the best photovoltaic performance, which was greatly increased to 8.09% by an optimized condition under standard global AM 1.5 solar light condition. The results show that the dyes based on this rigid donor are promising candidates for the improvement of the performance of DSSCs.