Efficient synthesis of triarylamine-based dyes for p-type dye-sensitized solar cells

Abstract

The class of triarylamine-based dyes has proven great potential as efficient light absorbers in inverse (p-type) dye sensitized solar cells (DSSCs). However, detailed investigation and further improvement of p-type DSSCs is strongly hindered by the fact that available synthesis routes of triarylamine-based dyes are inefficient and particularly demanding with regard to time and costs. Here, we report on an efficient synthesis strategy for triarylamine-based dyes for p-type DSSCs. A protocol for the synthesis of the dye-precursor (4-(bis(4-bromophenyl)amino)benzoic acid) is presented along with its X-ray crystal structure. The dye precursor is obtained from the commercially available 4(diphenylamino)benzaldehyde in a yield of 87% and serves as a starting point for the synthesis of various triarylamine-based dyes. Starting from the precursor we further describe a synthesis protocol for the dye 4-{bis[4′-(2,2-dicyanovinyl)-[1,1′-biphenyl]-4-yl]amino}benzoic acid (also known as dye P4) in a yield of 74%. All synthesis steps are characterized by high yields and high purities without the need for laborious purification steps and thus fulfill essential requirements for scale-up.

Limits on the use of cobalt sulfide as anode of p-type dye-sensitized solar cells

“…For this reason, we have continued here our study on p-DSCs with CoS anodes and P1-sensitized NiO photocathodes [21,23]. P1 is a dye known for having a stronger sensitizing action on NiO with respect to erythrosine B by virtue of the favourable electronic properties imparted by the triarylamine unit in P1 [40][41][42][43][44]. The content of the present paper is the analysis of the photoelectrochemical performance of the p-DSCs assembled with P1-sensitized NiO photocathodes [21,23] when the anodes are made of p-type CoS thin films (l < 10 µm).…”

N,N-Bis(4′-(hexyloxy)-[1,1′-biphenyl]-4-yl)thiophen-2-amine

“…However, among the previously synthesized derivatives of N,N-diarylthiophen-2amine, there were no derivatives where Ar = biphenyl. It is known that the use of a biphenyl group in triarylamino-containing donors can significantly increase the photovoltaic characteristics of dyes [8,9]. Previously, we synthesized bis(4 -(hexyloxy)-[1,1 -biphenyl]-4yl)amine 1 [10], which can be used as a precursor for the preparation of N,N-bis(4 -(hexyloxy)-[1,1 -biphenyl]-4-yl)thiophen-2-amine 2.…”

Quantum efficiency of the photo-induced electronic transfer in dye–TiO2 complexes

“…6 The dye, in both kinds of DSSCs, must have certain features for efficient performance, essentially a broad and strong absorption in the visible and near-red spectrum, chemical stability and appropriate redox potentials of the HOMO and LUMO states for the charge injection and recombination process to be successful. 19 Novel dyes have been studied to increase cell efficiency; for n-type DSSCs, sensitizers such as triphenylamine, [20][21][22] heterocyclic azo, 23 indoline, 24 triarylamine, 25 carbazole, 21,26 dithienylpyrazine, 27 coumarin, [28][29][30] porphyrins [31][32][33] and quinoline 34 -based dyes while for p-type DSSCs, coumarin, [35][36][37][38] porphyrin, 39,40 tryarilamine, 41 perylenediimide, 42,43 isoindigo, 44 squaraine, 45 arylamine 46 and carbazole 47,48 -based dyes have been utilized.…”