Molecular Design Strategy toward Robust Organic Dyes in Thin-Film Photoanodes

Abstract

The photo-, thermal, and water stability of dyes is indispensable for the commercialization of dye-sensitized solar cells, necessitating the development of systematic molecular design strategies to enhance the stability of the dyes. Therefore, we prepared dithieno­[3,2-b:2′,3′-d]­thiophene (DTT)-based dyes, by varying the functional group on the donor moiety (TP-1, H-; TP-2, methoxy-; TP-3, carbazolyl-; and TP-4, 2-ethylhexyloxy-). Among these dyes, TP-4 exhibits the highest power conversion efficiency of 8.86% (J sc = 15.9 mA cm–2, V oc = 0.76 V, FF = 0.73) with iodine electrolyte on a thin TiO2 active layer (3.5 μm), as well as strong resistance to photo-, thermal, and water stresses. UV–vis spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltaic spectroscopy were used to analyze the dyes. On the basis of these analyses, we suggest a molecular design strategy for simultaneously enhancing the stability of photo-, thermal, and water stresses.

Synthesis, Photophysical, and (Spectro)Electrochemical Properties of New Benzo[1,2-c][1,2,5]thiadiazoles and Benzo[1,2-d][1,2,3]triazoles Fused with Two Thiazole Rings

“…Acylation of diamines 12 and 13 with acid halides generated in situ from oxalyl chloride and carboxylic acids 14a – 14e led to the formation of N , N′ -diamides 15a – 15e and 16a – 16e in 69–86% yields. Carboxylic acids 14a and 14b were purchased from Sigma-Aldrich, and compounds 14d and 14e were prepared according to the procedure. − For the synthesis of 3-(2-ethylhexyl)-[2,2′-bithiophene]-5-carboxylic acid 14c , we used a method previously developed by us based on the Fiesselmann reaction. − …”

“…Synthesis of 9-hexyl-9 H -carbazole-3-carboxylic acid 14e and 4-(diphenylamino)­benzoic acid 14d is described in the literature. − The preparation procedures for compounds 2-hexyl-4-nitro-2 H -benzo­[ d ]­[1,2,3]­triazole ( 9 ) and benzo­[ c ]­[1,2,5]­thiadiazole-4,7-diamine ( 12 ) were previously reported. , …”

Imidazole-based AIEgens for highly sensitive and selective detection of picric acid

“…Compound R-CHO was synthesized according to previous literature. 51,52 The four imidazole derivatives ( M1–M4 ) containing α-cyanostilbene unit, triphenylamine (TPA), and tetraphenylethylene (TPE) were synthesized using a two-step reaction (Debus–Radziszewski reaction and Knoevenagel reaction). Their structures were fully characterized through FT-IR, 1 H NMR, 13 C NMR, and HR-MS.…”

Terpyridyl Ruthenium Complexes Functionalized with Conjugated Heterocycles for Panchromatic Dye-Sensitized Solar Cells

“…Device stability is critical to the practical application of DSCs, which mainly depends on the dye molecule, composition of iodide electrolyte (in particular the solvent), and the sealing technique. It was reported that the dyes must remain stable in the cation state for at least 10 s to realize a 10-year operation cycle. − Therefore, the TiO 2 thin films (thickness of 4 μm) sensitized with various Ru complexes and without a redox electrolyte were aged upon continuous irradiation of the AM 1.5 global simulated sunlight and thermal stress of 45 °C to examine the intrinsic photo and thermal stability of the Ru complexes immobilized on TiO 2 . The absorption spectra of the dye-sensitized films measured after the continuous irradiation for 0.5, 2, 4, 8, 12, and 16 h, respectively, are provided in Figure S14.…”