The effect of encapsulation of lithium atom on supramolecular triad complexes performance in solar cell by using theoretical approach

Abstract

Solar energy is the most important type of modern and renewable energies. If it displaces fossil fuels, can bring an end to concerns about finiteness of fuels, environmental pollution caused by fossil fuels, price fluctuations and energy crisis. Among the energy sources, due to the high potential of solar energies in wide areas of the world, it has great importance to researchers. Dye-sensitized solar cells (DSSCs) representation one of the most hopefully is appearing technologies for sunlight-to-electrical energy transformation. In the present research density functional theory and time-dependent semiempirical ZINDO/S (TD-ZINDO/S) methods have been used to investigate two series of triad system containing fullerene, porphyrin (P), and metalloporphyrin (Mp) as a dye sensitizer. In the first series, C60–porphyrin–metalloporphyrin (C60–P–Mp) triad system with M being Mg, Sc, Ti, Mn, Fe, Co, and Zn was investigated and in the second series, Li@C60 replaced with C60 (Li@C60–P–Mp). The influences of the type of metal in the P ring, and insertion of Li in the C60 on the energies of frontier molecular orbital and UV–Vis spectra have been studied. Structural optimizations of triad systems are carried out using the SIESTA package of program and the energy levels and electron density of the highest occupied molecular orbital and the lowest unoccupied molecular orbital, chemical hardness (η), electrophilicity index (ω), and electron accepting power (ω +). Moreover, the light harvesting efficiency was calculated by means of the oscillator strengths, which are obtained by TD-ZINDO/S calculation. Calculation results showed that three complexes Li@C60–P–ScP, Li@C60–P–CoP, Li@C60–P–MnP with low energy gap make these potential triad complexes in photovoltaic applications and are also excellent efficient as DSSC.