Effect of Deposition Layer of Titanium Dioxide (TIO2) Thin Film as Photoanode For Economically Sustainable Dye-Sensitized Solar Cell (DSSC) Application

Abstract

For decades, silicon solar cells had been established as commercialized solar cell. However, silicon solar cells require high cost and tedious fabrication techniques that utilized chemical which may be toxic to the environment. In this case, dye-sensitized solar cell (DSSC) has gained recognition in these recent years due to its simple and low-cost fabrication technique by utilizing natural resources when compared to commercial silicon solar cells which are fully chemical-based synthesis. DSSC is a thin film solar cell typically consist of a thin layer of porous titanium dioxide (TiO2) coated on a transparent conductive oxide such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO), light-absorbing dye, counter electrode and electrolyte to regenerate the electron. In this study, the effects of TiO2 thin film thickness were analyzed to determine whether the thickness of TiO2 thin film has significant effect on the performance of the DSSC device. TiO2 in this study was synthesized using sol-gel method with titanium (IV) butoxide used as the precursor. Spin coating method was utilized to deposit the thin film layers. Analysis on the structural, morphology, optical and electrical properties of the TiO2 thin film using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Ultraviolet-visible Spectrophotometry (UV-Vis) and 2-Point Probe respectively. The results for XRD pattern identified the production of the amorphous phase of TiO2 structured thin films, with a tendency towards anatase phase at 25° (highest peak on 3 deposition layers). FESEM images demonstrate that the TiO2 thin film with 3 layers has more porous, agglomerated, and compact morphology than the other two deposition layers. The bandgap energy of TiO2 thin films calculated from Tauc plot based on UV-visible absorbance spectra were 2.24 eV, 2.13 eV, and 2.04 eV for 1, 2, and 3 deposition layers, respectively. These properties indicate that 3 deposition layers is the optimized deposition layer of TiO2 thin film for DSSC application which will ensure good absorption of dye molecules onto the semiconducting metal oxide layer. Further research and new findings on other components like dye, electrolyte and counter electrode also necessary to improve the efficiency and stability of DSSC for future commercialization potential which will be more economically sustainable.