Investigation on Photoanode Modified With TiO2–ZnO–Ag Nanofibers in Dye-Sensitized Solar Cell Under Different Intensities of Illuminations

Abstract

A photoanode modified with silver (Ag)–zinc oxide (ZnO)–titanium dioxide (TiO2) composite nanofibers (NFs) was prepared and used in dye-sensitized solar cells (DSSCs). TiO2–ZnO–Ag NFs were added as an additional layer between the TiO2 layer and the electrolyte of the DSSC to improve photovoltaic performance. Photovoltaic parameters of DSSC were measured under air mass 1.5 (AM 1.5, 100 mW/cm2). The impedance between the interface of photoanode/dye/electrolyte was identified by electrochemical impedance spectroscopy (EIS). We also investigated power conversion efficiencies under various intensities of the incident light through filters. The results of the photovoltaic measurements show that the power conversion efficiency ( $\eta $ ) of the DSSC modified with Ag–ZnO–TiO2 composite NFs is 6.43%. Compared with the power conversion efficiency of the DSSC without modification (5.44%), it is increased by 18%. The incorporation of ZnO and Ag into TiO2 NFs can enable the rapid transport of electrons and suppresses the opportunity for electron recombination. From Nyquist plot, the DSSC modified with Ag–ZnO–TiO2 composite NFs shows higher impedance than the DSSC without modification. It means that the photoanode modified with Ag–ZnO–TiO2 composite NFs can successfully suppress electron recombination. Under the intensity of incident light at 30 W/cm2, the DSSC modified with Ag–ZnO–TiO2 composite NFs has the highest power conversion efficiency of 9.16%.