DFT and TD-DFT Calculations of Some Metal Free Phthalonitrile Derivatives for Enhancement of the Dye Sensitized Solar Cells |
| P.M. Anbarasana, P. Senthil Kumara, K. Vasudevana, S. Moorthy Babub and V. Aroulmojic
aDepartment of Physics, Periyar University, Salem - 636 011, India bCrystal Growth Centre, Anna University, Chennai - 600 025, India cPROTOS Research Institute, Via Flavia 23/1, C/O Sviluppo Italia, 34147 Trieste, Italy |
| Received: January 1, 2010; Revised version: April 20, 2010; in final form: May 10, 2010 |
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| The geometries, electronic structures, polarizabilities, and hyperpolarizabilities of organic dye sensitizers 3,4-pyridine-di-carbo-nitrile, 3-amino-phthalo-nitrile, 4-amino-phthalo-nitrile and 4-methyl-phthalo-nitrile were studied based on density functional theory using the hybrid functional B3LYP. Ultraviolet-visible spectra were investigated by time dependent density functional theory. The features of electronic absorption spectra in the visible and near-UV regions were assigned based on time dependent density functional theory calculations. The absorption bands are assigned to π → π* transitions. Calculated results suggest that the three lowest energy excited states of 3,4-pyridine-di-carbo-nitrile, 3-amino-phthalo-nitrile, 4-amino-phthalo-nitrile and 4-methyl-phthalo-nitrile are due to photoinduced electron transfer processes. The interfacial electron transfer between semiconductor TiO2 electrode and dye sensitizers 3,4-pyridine-di-carbo-nitrile, 3-amino-phthalo-nitrile, 4-amino-phthalo-nitrile and 4-methyl-phthalo-nitrile is due to an electron injection process from excited dyes to the semiconductor's conduction band. The role of amide and methyl groups in phthalonitrile in geometries, electronic structures, and spectral properties were analyzed in a comparative study of 3,4-pyridine-di-carbo-nitrile, 3-amino-phthalo-nitrile, 4-amino-phthalo-nitrile and 4-methyl-phthalo-nitrile for the improvement of dye sensitized solar cells. |
| DOI: 10.12693/APhysPolA.119.395 PACS numbers: 78.66.Qn, 31.10.+z, 71.15.Mb, 32.30.-r |