The natural dye extracted from lawsonia inermis seed was
successfully used as dye sensitizer for pure and pre dye treated
TiO2 nanoparticles synthesized using conventional and modified
sol–gel techniques. The PXRD analysis confirms the anatase phase
of TiO2 nanoparticles calcined at 250 C. The UV–vis absorption
studies confirms the more dye absorbance in pre dye treated TiO2
and FTIR spectra confirms the formation of TiO2 in both sol–gel processes.
The SEM images confirm the improved morphology and reduced
agglomeration due to pre dye treatment. DSSCs were
fabricated using conventionally prepared and pre dye treated TiO2
sensitized by lawsone pigment rich natural dye. The light to electron
conversion efficiency of conventional and pre dye treated TiO2
based DSSCs are 1.0% and 1.47% respectively. The modified sol–gel
process yielding pre dye treated TiO2 nanoparticles showed 47%
improvement in efficiency and is a promising methodology in terms
of more dye adsorption, less dye aggregation. Therefore, the natural
dye extract of lawsonia inermis seed can be used as an effective
photo sensitizer and the modified sol–gel synthesis process of
producing pre dye treated TiO2 nanoparticles can be adopted for
making DSSCs with improved efficiency.