MULTITUDE EFFECT OF ALUMINIUM SULFATE-DOPED TIO2 PASSIVATION PHOTOELECTRODE FOR PERFORMANCE ENHANCEMENT OF DYE-SENSITIZED SOLAR CELLS, DSSCS

Abstract

In this study, aluminum sulphate hydrate, Al₂(SO₄)₃-doped TiO₂ based passivation photoelectrode (ADTP) was successfully proved to be a promising method of improving DSSCs. Here, ADTP based photoelectrodes were obtained by varying the percentages of Al₂(SO₄)₃ added to the nanoparticles of Titanium dioxide (TiO₂). The morphological images of the ADTPs obtained using field emission scanning electron micrograph (FESEM) indicate their compositional behavior, which include two different sizes (different atomic radii) of titanium and aluminium nanoparticles. Furthermore, the occurrence of the Ti⁴⁺/Al³⁺ ions substitution in the ADTP film was then supported by UV-Vis spectroscopy analysis. Meanwhile, the fourier transform infrared (FTIR) spectroscopy analysis revealed that the ADTP samples have higher OH^- functional group which is attributed to the formation of the Al(OH)₃ mediators. These mediators enhance the binding of dye molecules to the TiO₂ nanoparticles, thereby improving the adsorption of the dye molecules onto the ADTP surfaces. The subsequent electrochemical impedance spectroscopy (EIS) analysis revealed that all ADTP photoelectrodes exhibited higher conductivity TiO₂ film and trap states, which serves for lower interfacial resistance, inhibiting back recombination and promoting more carriers for electron conduction (photocurrent density, J_SC). The integrated properties of the ADTP photoelectrode that improve interfacial resistance, induce higher dye adsorption and reduce back electron recombination resulted in a 0.47 % increase in power conversion efficiency (PCE) of the 3-ADTP-based DSSC.