Enhanced photovoltaic behavior of dye sensitized solar cells fabricated using pre dye treated titanium dioxide nanoparticles

Dye sensitized solar cells (DSSC) were successfully fabricated using titanium dioxide nanoparticles sensitized by a new natural photo sensitizer extracted from Acacia concinna pod. Pure titanium dioxide (TiO₂) nanoparticles in anatase phase were synthesized by sol–gel process. And, pre dye treated TiO₂ nanoparticles were prepared by modified sol–gel process which has improved properties, like uniform dye adsorption, reduced agglomeration, improved morphology and less dye aggregation. The A. concinna pod extract, which is rich in acacic acid (saponins) as major pigment was used to sensitize pure and pre dye treated TiO₂ nanoparticles. The pure and pre dye treated TiO₂ nanoparticles were subjected to structural, optical, spectral and morphological studies. Low cost and environment friendly dye sensitized solar cells fabricated using pre dye treated and conventionally prepared TiO₂ nanoparticles sensitized by A. concinna pod extract showed solar light to electron conversion efficiencies of 0.69 and 1.17 % respectively. The pre dye treated TiO₂ based DSSC showed 69 % improvement in efficiency when compared to that of conventional DSSC.