Influence of TiO2 film thickness on photovoltaic properties of dye-sensitized solar cells

Abstract

Generally, the dye-sensitized solar cells DSSCs are composed of a photoanode, a redox-coupled electrolyte, and a counter electrode. The nanocrystalline porous TiO2 film is one of the most employed frequently photoanode materials in this type of solar cells due to its excellent optoelectronic properties. It significantly influences the photon-electron conversion efficiency of the solar cell, because of its good photo-excited electron transportation and dye adsorption. The surface morphology, crystalline phase, particle size, surface area, porosity, and dispersion of TiO2 nanoparticles are the various influencing factors which determine the properties of DSSCs. In particular, the thickness of the photoanode is known to be one of the crucial factors determining the efficiency of solar cells. These properties strongly relate to the TiO2 electrode method of fabrication and its parameters. Dye-sensitized solar cells based on TiO2 films with different printing layers were fabricated by screen printing method. The prepared samples were characterized by scanning electron microscopy SEM and UV-Vis absorption spectroscopy. The effects of film thickness on the current-voltage characteristics of DSSCs were also investigated.