Triphenylamine-based tri-anchoring organic dye with enhanced electron lifetime and long-term stability for dye sensitized solar cells

Abstract

An organic sensitizer with a multi-anchoring system is a versatile methodology for enhancing the stability and conversion efficiency of dye-sensitized solar cells (DSSCs). Triphenylamine dyes (TPA3T1A similar to 3A) containing different numbers of anchoring groups are synthesized to determine the correlation between the number of anchoring groups and photovoltaic properties as photosensitizers for DSSCs. The adsorption properties of the dyes on TiO2 electrode were examined by ATR-FT-IR, which show that a mono-anchoring TPA3TIA system adsorbs in monodentate ester-type mode, and the three carboxylic acids in TPA3T3A adsorbs in bidentate bridging mode. The multi-anchoring dye exhibits strong electronic coupling with TiO2, providing an efficient charge injection rate. Moreover, they increased the electron lifetime significantly by suppressing the charge recombination probability. This synergistic effect enables the fabrication of efficient photovoltaic devices. Furthermore, enhanced long-term stability is also observed in the DSSCs containing a tri-anchoring system compared to the mono- and bi-anchoring systems. (C) 2016 Elsevier B.V. All rights reserved.