Optical Properties of Natural Dye Leaf Extracts and Nanostructured TiO2 Particles as Photosensitizers for Dye-Sensitized Solar Cells

Abstract

A threat to the energy production in the world is emerging mainly because of the shortage of energy resources and world industrialization. Although the cost factor is also a problem here, the future of solar energy is now growing and its conversion efficiency is also increasing. An important realization that can be made is that a dye-sensitized solar cell is a means of refining solar energy conversion technology, in which the use of wide bandgap semiconductors is based on photocurrent. Among the elements of the dye –sensitized solar cell, the dye as a sensitizer determines the performance of the cell. Common natural dyes are obtained from leaves, flower petals, and roots for instance. Considering the aspect of simplicity and cost of natural dyes, less complex extraction process than synthetic dyes and being friendly to the environment, researchers are striving to find ways of replacing the synthetic dyes with natural dyes. Here, TiO2 was prepared with the Sol-gel spin coating method with titanium tetraisopropoxide, isopropanol, acetic acid, and deionized water as precursors. The results showed that there was changes in the optical properties like transmittance, reflectance, and bandgape energy when the dye leave extract of Mangifera Indica, Manihot Esculenta, and Hibiscus Sabdariffa was examined. Morphological and compositional properties of the nanostructured TiO2 are also ascertained.