The role of the donor group and electron-accepting substitutions inserted in π-linkers in tuning the optoelectronic properties of D–π–A dye-sensitized solar cells: a DFT/TDDFT study

Abstract

A series of metal-free organic dyes with the D–π–A–A arrangement and with different donor and acceptor groups have been designed theoretically.

Computational study of linear carbon chain based organic dyes for dye sensitized solar cells

“…Dyes with higher performance were obtained by including a rigid aromatic system in the molecular structure thus increasing the planarity and, in turn, favoring the electron ow between donor and acceptor moieties. [39][40][41] The acceptor-anchoring groups are mainly represented by cyanoacrylic and benzoic acid moieties which are present in the vast majority of DSSC with best performance, see all references reported above. Various pconjugated bridges have been employed with aim of favoring the electrical communication between donor and acceptor.…”

New organic dye-sensitized solar cells based on the D–A–π–A structure for efficient DSSCs: DFT/TD-DFT investigations

“…The charge-transfer rate ( k ) also influences a DSSC device's efficiency, which may be defined as follows: 26 where V is the charge-transfer coupling constant, T is the temperature, k b is the Boltzmann constant, and the λ total is the reorganization energy. Except for the λ total , all the parameters in eqn (14) are believed to be constants; while a lower λ total will expedite electron transport and boost the J sc .…”

“…14 In general, most used organic dyes for DSSCs are articial sensitizers that possess the donor-p-spacer-acceptor (D-p-A) molecular architecture, which is intended to provide intramolecular charge transport (ICT) from the donor unit (D) to the acceptor group (A) via the pspacer. [15][16][17] Other potential structures of articial sensitizers, including D-A-p-A, [18][19][20] D-D-p-A, 21,22 (D-p-A) 2 , 23,24 D-p-A-A, 25,26 and A-p-D-p-A, 27,28 have also been established and gained signicant importance due to their high efficacy, 29 but the most common structure is (D-p-A) because it facilitates electron movement, which improves the efficiency of dyes and allows them to be used in DSSCs. [30][31][32] Since the efficiency of a DSSC cell is highly dependent on the photosensitive dye used in the cell, the following points can be used when designing the cell to improve and raise the efficiency of DSSCs: (a) it must include the most appropriate p-spacers between the electron donor and the acceptor; (b) it is important to have a broad and strong absorption band capable of covering practically all the visible and near-infrared spectral region (NIR); (c) appropriate redox and oxidation potentials of the compound should be investigated to ensure regeneration; (d) a high electron connection is necessary between the molecules and conduction band of the semiconductor (TiO 2 ) to accelerate the transfer of electrons from the dye to TiO 2 .…”

Design of a D–Di–π–A Architecture with Different Auxiliary Donors for Dye‐Sensitized Solar Cells: Density Functional Theory/Time‐Dependent‐Density Functional Theory Study of the Effect of Secondary Donors

“…The charge transport rate (k) also influences the efficiency of the DSSC device, which is formulated as follows (Equation (15)): [74] k =…”