Natural dye extract of lawsonia inermis seed as photo sensitizer for titanium dioxide based dye sensitized solar cells

•Natural dye extract of lawsonia inermis seed as dye sensitizer for DSSC.•Modified sol–gel process has yielded pre dye treated TiO2.•Pre dye treated TiO2 results better dye absorption, less agglomeration, dye aggregation.•Efficiency 1% for conventional, 1.47% for pre dye treated DSSC.•47% improvement in efficiency due to pre dye treatment with natural dye.

Natural dye extract of lawsonia inermis seed were used as photo sensitizer to fabricate titanium dioxide nanoparticles based dye sensitized solar cells. Pure titanium dioxide (TiO2) nanoparticles in anatase phase were synthesized by sol–gel technique and pre dye treated TiO2 nanoparticles were synthesized using modified sol–gel technique by mixing lawsone pigment rich natural dye during the synthesis itself. This pre dye treatment with natural dye has yielded colored TiO2 nanoparticles with uniform adsorption of natural dye, reduced agglomeration, less dye aggregation and improved morphology. The pure and pre dye treated TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies. Dye sensitized solar cells (DSSC) fabricated using the pre dye treated and pure TiO2 nanoparticles sensitized by natural dye extract of lawsonia inermis seed showed a promising solar light to electron conversion efficiency of 1.47% and 1% respectively. The pre dye treated TiO2 based DSSC showed an improved efficiency of 47% when compared to that of conventional DSSC.

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