Effect of Metal Doped-TiO2 on the Performance of Dye Solar Cells (DSCs)

Abstract

Doping of TiO2 with metal or non-metal elements draws much attention in tailoring the properties of photoanode in Dye Solar Cells (DSCs). In this study, liquid impregnation method was implemented in synthesizing metal-doped TiO2 of Al, Fe, Ni and Zn in order to study the effect of doping of metals in TiO2 photoelectrode materials on the performance of integrated DSCs. The synthesized samples were then screen printed onto FTO glass, sensitized with N719 and assembled in sandwich layer with Pt counter electrode. The performance of integrated DSCs was verified using I-V characteristics under illumination of simulated AM 1.5 solar radiance. EIS characterization was done to further understand the electrochemical properties of metal-doped TiO2 photoelectrode of a DSC. The results show that doping with Al at concentration of 0.5 moles metal ion over 100 moles of Ti4+ ions can improve the overall performance efficiency of a DSC from 3.656% to 4.540%. However, Ni and Zn-doped TiO2 photoelectrode were found to improve the Voc whilst DSC with Al-doped TiO2 exhibits the highest Isc and the lowest Rdc resulting in the highest efficiency compared to other metal doped TiO2 DSCs. The doping could influence the electron transport in the photoelectrode materials and interface charge recombination between the photoelectrode materials and the redox electrolyte.