Effect of pH-Controlled Titanium Dioxide Synthesis on Solar Cell Performance and its Relevance to Renewable Energy Economics

Abstract

Titanium dioxide (TiO2) is a transparent to visible light n-type wide band gap semiconductor. Employing a wide band gap semiconductor and sensitizer dyes adsorbed on it, Dye-sensitized Solar Cell (DSSC) can convert visible light into electrical energy. TiO2 paste in this study was prepared using TiO2 powder synthesized by the sol- gel method with differing pH values. The comparison study on the phase, morphological, and optical characterizations of thin films of these TiO2 pastes was carried out using 2-Point Probe, X-ray diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM), and Ultraviolet-visible (UV–vis) spectroscopy in this study. The XRD pattern detects the occurrence of the amorphous phase of TiO2- structured thin films in all thin films. FESEM images show that TiO2 with pH4 and pH6 consists of less agglomerated particle distribution compared to pH8, which may impede photocatalytic activity. The bandgap energy of TiO2 thin films was 2.25 eV, 2.15 eV, and 1.56 eV at pH4, pH6, and pH8, respectively. A pH of 6 is optimum in sol-gel synthesis as it facilitates a balanced hydrolysis and condensation rate, resulting in a consistent, pre- ordered amorphous gel network that can effectively crystallize into a pure anatase structure. This study is novel in its emphasize correlation of sol–gel synthesized TiO? at different pH values, which shows that pH has a significant impact on surface morphology, optical bandgap, and particle agglomeration. These factors essential to dye adsorption and electron transport in DSSC applications. The results obtained suggest improvement on the coating method for better optimization for DSSC application.