Preparation of natural dyes from different plants as photosensitizer in modified SnO2 photoanode films for dye sensitized solar cell application

Abstract 

The study focuses on the potential of naturally occurring dyes as photosensitizers in dye-sensitized solar cells (DSSCs). DSSCs are a type of solar cell that uses chemicals called photosensitizers to absorb energy from visible light and produce excited electrons. In 1991, Grätzel and his co-workers developed DSSCs, which have gained attention in recent years. However, the ruthenium-based compounds used as photosensitizers are expensive, and research suggests that organic dyes could be viable alternatives. The study aimed to incorporate natural dyes extracted from five different plant leaves into silver nanoparticles to enhance the performance of the DSSCs' photo-anode. The silver nanoparticles were synthesized using a silver nitrate precursor, and SnO2-based photo-anodes were fabricated using the doctor blading technique. The synthesized nanoparticles, extracted dyes, and fabricated thin film devices were characterized using UV-Vis spectroscopy. The results showed that the addition of nanoparticles broadened the absorption band of the spectra for most dyes, except for Sida acuta, which exhibited prominent peaks. The optical absorption of the silver nanoparticles ranged from 350 to 460 nm, with an absorption peak at 2.56 a.u. The extracted dyes from different plants exhibited varying absorption coefficients within specific wavelength ranges when combined with nanoparticles.

Overall, this study concludes that incorporating nanoparticles with the extracted dyes expanded the absorption band of the spectra, indicating their potential for use in photovoltaic applications, except for Sida acuta, which showed distinct peaks. This research contributes to the exploration of natural dye-based photosensitizers as cost-effective alternatives to ruthenium-based compounds in DSSCs.