Experimental Study of the Effects of Natural Dyes on the Function of Solar Cells Based on the Nanostructure of Nanoparticle/TiO2 Nanowires

To take full advantage of the properties of dyes, nanostructured solar cells should be available because in this case a better interaction between the dye and the background can be created due to the high surface-to-volume ratio. The aim of this research was the experimental investigation of natural dyes influence on the function of solar cells based on nanostructure of TiO2 nanoparticle/nanowires. For this purpose, an innovative nanostructure was fabricated, and three natural dyes of saffron, turmeric and rubia-tinctorum were used as a sensitizer due to their abundance, availability, environmental compatibility, safety and easy processing. The absorption spectra of the dyes were examined by a spectrophotometer. The absorbance peak for saffron, turmeric and rosin pigments were obtained at 510, 500 and 460 nm, respectively. The photoanode’s morphology was investigated by a scanning tunneling microscope. The characterization and performance of solar cells were carried out by the solar simulator device. The microscopic analysis showed that the composition of nanoparticles and nanowires of TiO2 builds the porous structure with large surface-to-volume ratio, playing a great role in the amount of dye absorption and efficiency of solar cells. Generation of short electron transfer path, facilitating the transfer of electrons to semiconductor conductive band, and reducing recombination reactions were the main advantages of this structure. The evaluations also showed that rubia-tinctorum dye performed better in enhancing the efficiency of solar cells based on TiO2 nanoparticles/nanowires, improving efficiency by 4.04% compared to other available dyes.