New Triphenylamine-Based Dyes for Dye-Sensitized Solar Cells

Abstract

A series of new conjugated metal-free organic dyes (TC1, TC2, TC3, and TC4) comprising triphenylamine (TPA) moieties as the electron donor and cyanoacetic acid moieties as the electron acceptor/anchoring groups were designed at the molecular level and developed for the use in dye-sensitized solar cells (DSCs). Quantum chemical calculations have been performed to gain insight into structural, electronic, and optical properties of the as-synthesized sensitizers. The time-dependent density functional theory calculations allowed assignment of the experimental spectroscopic data. It is found that the photovoltaic performance of the DSCs with the as-synthesized dyes can be improved by enhancing the electron-donor ability and extending the π-conjugated bridge of the dyes. In particular, the DSCs based on 2-cyano-5-(4-(phenyl(4-vinylphenyl)amino)phenyl) penta-2,4-dienoic acid dye ( TC4) showed an open circuit voltage of 652 mV, a short circuit photocurrent density of 11.5 mA cm -2 , and a fill factor of 0.64, corresponding to an overall light to electricity conversion efficiency of 4.82% under AM 1.5 irradiation (100 mW cm -2 ). This result reveals that efficient electron injection from the excited sensitizer to the conduction band of titania film occurs, owing to the more delocalizing electrons of the bridge and donor part of the dyes.

Acene‐Modified Triphenylamine Dyes for Dye‐Sensitized Solar Cells: A Computational Study

“…Among the metal-free organic dyes, TPA-based dyes, with TPA derivatives and the cyanoacrylic acid moiety as electron donor and electron acceptor units, respectively, have displayed prominent light-to-electrical energy conversion efficiencies in DSSCs. [8,[14][15][16][17][18] The TPA group is expected to confine the cationic charge from the semiconductor surface and therefore efficiently prevent charge recombination. The TPA moiety with a sizable steric hindrance can also hamper unfavorable dye aggregations at the semiconductor surface.…”

“…The TPA moiety with a sizable steric hindrance can also hamper unfavorable dye aggregations at the semiconductor surface. The modifications of TPAbased organic dyes have been intensively investigated, [4,5,[14][15][16][17] and the record highest solar energy conversion efficiency of TPA dyes has exceeded 10 %. [19] The overall conversion efficiency (h) of the DSSCs is determined by the short current density (J SC ), the open circuit potential (V OC ), the fill factor (ff) of the cell, and the intensity of the incident light (I s ) [Eq.…”

A TD-DFT study of the effects of structural variations on the photochemistry of polyenedyes

“…Among the donor moieties, N, N-dimethylaniline group, 9,10 coumarins, [11][12][13][14][15][16][17] tetrahydroquinolines, 18,19 pyrrolidine, 20 carbazoles, 21 diphenylamine, 22 triphenylamine, [23][24][25][26] etc have been widely used for the dye synthesis. A linker moiety is a spacer added between the donor and acceptor moieties.…”

“…A linker moiety is a spacer added between the donor and acceptor moieties. Different π-conjugated linker groups such as the -C=C-chain, [9][10][11][12][13]16,24 thiophene units (and its derivatives), 11,[14][15][16][17][18][19][20][21][22]26 etc have also been investigated. In particular two types of acceptor/anchor groups, namely cyanoacrylic acid, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] and carboxylic acid [27][28][29] are widely used in organic dyes for DSSC.…”

Geometrical, electronic structure, nonlinear optical and spectroscopic investigations of 4-(phenylthio)phthalonitrile dye sensitizer for solar cells using quantum chemical calculations

“…In view of the limited ruthenium resource and the heavy-metal toxicity, metal-free organic dyes have received surging research interest in recent years [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Because of their high molar absorption coefficient, relatively simple synthesis procedure, various structures and lower cost in contrast to a ruthenium dye and the flexibility in molecular tailoring of an organic sensitizer provides a large area to explore [22][23][24]. Moreover, recently a rapid progress of organic dyes has been witnessed reaching close to 10.0% efficiencies in combination with a volatile acetonitrile-based electrolyte [25].…”