Designing of PC₃₁BM‐based acceptors for dye‐sensitized solar cell

Abstract

Three push‐pull dyes with triphenylamine as donor, thiophene as spacer and fullerene‐based acceptors have been designed using density functional theory (DFT) for dye‐sensitized solar cells (DSSCs). Here, we have done a systematic case study by varying the acceptor of dye. PCBM type of acceptors are chosen. However, the main focus lies on the fact that fullerene C60, which is used as conventional fullerene in PCBM, is replaced by C30. Further, two more structures are derived, where C30 is changed by two of its doped counterparts, C10B10N10 and C10B10P10. Structural integrity of these dyes is checked and found to be stable. Their electronic properties also provide a good insight into their characteristics. Highest occupied molecular orbital (HOMO) energy level of the dyes is positioned under the redox potential of redox couple, , which means that the dyes can be regenerated. LUMO energy value of dyes with C30 and C10B10N10 lies above the conduction band of semiconductor, TiO2, and hence electrons from the excited state of the dyes can be injected into the conduction band edge of TiO2. For C10B10P10, lowest unoccupied molecular orbital (LUMO) lies slightly below the conduction band of TiO2 (for B3LYP functional). Therefore, few more configurations of C10B10P10 have been checked by replacing B and P atoms with C atoms. Notably, incorporation of solvent rules out this exception and all the dyes become eligible for electron regeneration also. Time‐dependent DFT (TDDFT) studies throw light on their photochemical properties, which is one of the interim criteria for any system getting selected as a dye in the DSSCs.

Mechanisms of acid generation from ionic photoacid generators for extreme ultraviolet and electron beam lithography

“…34,35 The integral equation formalism polarizable continuum model (IEFPCM) was applied in all the DFT calculations to approximate the solid environment, with the dielectric constant set to 4. 36–41…”

Self-Assembled Monolayers of Push–Pull Chromophores as Active Layers and Their Applications

“…Therefore, it is necessary to develop the energy-level engineering of chromophores on the metal oxide surface, which can be achieved by the right design of push-pull chromophores through the nature and length of the π-bridge groups, together with using various acceptor and donor groups with different electron affinities. Among the studies on various acceptors, one can cite the work of Keremane and co-workers [72] (Figure 4), Paul and Sarkar on PCBM-based acceptors (Phenyl-C61-butyric acid methyl ester) [73], and Mustafa et al [74] on the theoretical study of the influence of the acceptor's nature. For good DSSC operation, it is mandatory that the dyes be grafted onto the inorganic mesoporous semiconductor oxide film in controlled, organized stacks, enabling the determination of energy alignments and high charge-transfer kinetics to improve light harvesting [67].…”

On the study of dye-sensitized solar cells with high light harvesting efficiency and correlation of its chemical reactivity parameters with overall performance

“…A suitable donor when compiled with a suitable acceptor promises a dye with superior performance, and for this to be the case, often donors are tested with different acceptors and making comparisons on their overall e ciency thus making their selection judiciously. The use of fullerene as an acceptor has served as a milestone in the designing of dyes for DSSCs [25,26] on account of fullerene possessing highly delocalised -electrons on its spherical surface which facilitates its ability to withdraw -electrons from the dye. But even so, its utilization is limited as fullerene is not easy to synthesise.…”