An investigation on titanium doping in reduced graphene oxide by RF magnetron sputtering for dye-sensitized solar cells

A study investigating the effects of titanium (Ti) atoms sputtered from different sources on substrate distance was attempted in order to effectively dope a reduced graphene oxide (rGO) thin film surface. Factors such as crystallinity, morphology, phase formation, light absorption, and surface chemical state of rGO-TiO₂ were investigated. As a result, functional groups or chemical states revealed the presence of Ti-O-C in rGO-TiO₂ nanocomposite after the sputtering process. The titanium source from the target was of Ti³⁺ species as determined using X-ray photoelectron spectroscopy (XPS). It was found that average sized Ti³⁺ ions of around 59.4 nm were incorporated into the rGO nanosheet. A customized Dye-Sensitized Solar Cells (DSSCs) device was fabricated with the photo-anode consisting of sputtered rGO-TiO₂ nanocomposite. After optimization, the Ti target allocated with 10 cm-apart FTO glass-coated rGO nanosheet and 0.67 cm² active area exhibited an ideal PCE of 6.60%, which is remarkably higher than the usual 5 cm sputtering distance the sample (1.90%) had achieved.