Sensitization of Nanocrystalline Titanium dioxide Solar Cells using Natural Dyes: Influence of Acids Medium on Coating Formulation

Abstract

Dye Sensitzed solar cells (DSSC) has drawn attention as an alternative to the silicon based solar cells due to their low fabrication cost and reasonably high efficiency. This paper presents an approach on the development of DSSC and the photoelectrochemical effect and conversion efficiency available natural dye sensitized Titanium dioxide (TiO2) photoelectrode with respect to acid treatment of coating formulation. Acid treatment on TiO2 paste was observed using an organic acid (citric acid) and an inorganic acid (nitric acid) considering a base natural dye (red spinach). Optimal concentration of these acids (organic and inorganic) was determined by cell performance. Five different natural dyes were used as sensitizers of DSSC and their performance was observed considering photoelectrochemical output and UV-visible absorption using optimized acid concentrations. Citric Acid treated cells with red spinach dye as sensitizer produced the best performance with 1mAcm-2 current density with 505mV potential. It was found that DSSC showed better photovoltaic performance and higher conversion efficiency when the TiO2 paste was treated by organic acid than inorganic acid and red spinach dye proved to be the best sensitizer.