Fabrication of dye-sensitized solar cells using titanate nanotube-ultrasonicated TiO2 bilayer photoelectrodes for enhanced specific surface area and electron transport efficiency

초록

Dye-sensitized solar cells (DSSC) are promising third-generation photovoltaic devices due to their environmental friendliness and cost-effectiveness. However, the relatively low energy conversion efficiency necessitates further research on improving photoelectrode structures. In this study, a TN/US bilayer photoelectrode was designed by combining synthesized titanate nanotubes (TNT) with ultrasonically treated TiO2 (US TiO2), and its electron transport characteristics and photovoltaic performance in DSSCs were systematically analyzed. X-ray diffraction (XRD) analysis confirmed the formation of titanate, and scanning electron microscopy (SEM) confirmed the fibrous structure of TNT and improved dispersion of TiO2 particles due to the ultrasonic treatment process. Brunauer-Emmett-Teller (BET) analysis indicated a high specific surface area of 388.19 m2/g for TNT, contributing to enhanced dye adsorption. Electrochemical impedance spectroscopy (EIS) revealed that the TN/ US bilayer photoelectrode exhibited the lowest electron transfer resistance (14 k Omega), indicating a highly efficient charge transport pathway. Measurements of chemical capacitance and recombination resistance further confirmed superior charge storage (4.38 F cm2) and reduced electron recombination (20.8 Omega cm2), representing a 34% improvement over Pure TiO2-based DSSC. Based on these results, the TN/US bilayer photoelectrode improved electron generation, transport, and recombination suppression, thereby increasing the energy conversion efficiency of the DSSC to 2.59%.

키워드