Pre dye treated titanium dioxide nanoparticles synthesized by modified sol–gel method for efficient dye-sensitized solar cells

Pure and pre dye treated titanium dioxide nanoparticles were prepared by sol–gel and modified sol–gel methods, respectively. The pre dye treatment has improved the properties of TiO, such as uniform dye adsorption, reduced agglomeration, improved morphology and less dye aggregation. The brazilein pigment-rich Caesalpinia sappan heartwood extract was used as natural dye sensitizer for pure and pre dye treated TiO nanoparticles. Low cost and environment friendly dye-sensitized solar cells (DSSC) fabricated using pure and pre dye treated TiO nanoparticles sensitized by natural dye showed solar light to electron conversion efficiencies of 1.09 and 1.65 %, respectively. The pre dye treated TiO-based DSSC showed 51 % improvement in efficiency when compared to that of conventionally prepared DSSC.