Natural Anthocyanins Based Dye Sensitized Solar Cell: A Review Paper.

Anthocyanins are anthocyanidins (phenyl-2-benzopyrilium) coordinated with glycosides at position 3 and/or 5. The carbonyl and hydroxyl groups of anthocyanin molecules can be chemically bound on to the surface of semiconductors thereby providing favourable condition for charge injection. Generally, bare wide band gap semiconductors exhibit no absorption in the visible range. However, after coordination with dye molecules, the absorption related to both transitions from Valence Band (VB) to Conduction Band (CB) and from Highest Occupied Molecular Orbital (HOMO) to Lowest Unoccupied Molecular Orbital (LUMO) are revealed implying the sensitization of photoanode. Anthocyanins have proven to be among the most versatile photosensitizers of wide band gap semiconductors in the Dye Sensitized Solar Cells (DSSCs). This paper reviews the potential of anthocyanin pigments from different sources as photosensitizers of wide band gap semiconductor in DSSCs. The review focuses on the influence of different parameters such as the nature of the dye and its preparation, type and morphology of photoelectrode, nature of electrolyte, additives and co-absorbers on performance of DSSCs. [ABSTRACT FROM AUTHOR]