Comparative analysis of triarylamine and phenothiazine sensitizer donor units in dye-sensitized solar cells

Abstract

A homologous set of dyes that differ only in the donor fragments, namely phenothiazine (PTZ) and triarylamine (TPA) units, were evaluated in dye-sensitized solar cells (DSSCs). The novel PTZ-based dye differs from the TPA-based dye in that it contains a sulfur bridge that planarizes two aromatic rings and enables higher dye loading and higher stability in the oxidized form. These positive features notwithstanding, the superior absorptivity of devices sensitized by TPA-based dyes resulted in significantly higher power conversion efficiencies (PCEs) than those sensitized by PTZ-based dyes.

Bio-inspired Molecular Redesign of a Multi-redox Catholyte for High-Energy Non-aqueous Organic Redox Flow Batteries

“…It can be speculated that the planar molecular geometries of the radical cation and dication effectively delocalized the additional charges, leading to the remarkable redox stability of BMEPZ. 54,55 It is noteworthy that many p-type ROMs except BMEPZ tend to be very unstable when they are oxidized by two electrons, resulting in fast decay of the cycle performance. 13,31 Electrochemical Performance of BMEPZ/FL Flow Cell Cycling tests of flow cells employing BMEPZ as the catholyte and FL as the anolyte were performed using a custom flow cell (see the Experimental Procedures section for further details) to investigate the electrochemical performance in a near-practical system.…”

Synthetic Efforts to Investigate the Effect of Planarizing the Triarylamine Geometry in Dyes for Dye-Sensitized Solar Cells

“…This blue shift is noted in several studies comparing 10 H -phenothiazine dyes to conventional phenothiazine dyes 54 and to triarylamine dyes. 55 , 56 The absorption properties of dyes that adopt this configuration suffer from a poor orbital mixing between the donor and acceptor since the acceptor part of the conjugated system sits perpendicular to the phenothiazine donor. 56 An example of the opposite is seen for the double phenoxazine dye, POZPOZ-Th , where more of the aromatic system of the donor is brought into the plane of the acceptor.…”

Recent developments in metal‐free organic sensitizers derived from carbazole, triphenylamine, and phenothiazine for dye‐sensitized solar cells

“…30 Thus, metal-free organic sensitizers have drawn greater attention over metal-based organic sensitizers due to their low toxicity, high structural flexibility, environment friendly nature, high MECs, and facile synthesis. 31,32 It is to be noted that previously, several chromophores such as indoline, 33,34 coumarin, 35,36 phenothiazine, 37,38 carbazole, 39,40 triarylamine, 41,42 tetrathiafulvalene, 43,44 etc were used in the assembly of organic sensitizers. Better structure-property relationship elucidation will encourage the better use of these dyes in DSSCs.…”

“…Six N-dimethylfluorenylcarbazole dyes have been synthesized by Liu et al 79 The dye contains CZ donor with or without a benzothiadiazole auxiliary acceptor dependent on benzene, furan, and thiophene sequence of quinoline-bridge (36)(37)(38)(39)(40)(41). The existence of benzothiadiazole extends the absorption spectra and promotes lightharvesting capacities, which gain improved IPCE spectra and enhanced J SC accordingly.…”