Fabrication and performance of nanoporous TiO2/SnO2 electrodes with a half hollow sphere structure for dye sensitized solar cells

Abstract

The incorporation of nano-crystalline semiconductors with novel kinds of ordered microstructure is a very important area of research in the field of dye sensitized solar cells. A sol-gel method involving hydrolysis of titanium isopropoxide was used to form TiO2 nanoparticles on the surface of SiO2 spheres. In this process, 1, 5, or 10 wt% of SnCl2.2H(2)O was added to the sol-gel solution. To prepare TiO2/SnO2 nanoparticles with a half hollow sphere structure, SiO2 was removed with NaOH solution. The crystal phase, crystal shape, and surface properties of the metal oxide nanocrystals were studied by x-ray diffraction and scanning electron microscopy. The photovoltaic performance of the TiO2/SnO2 nanoparticles with half hollow sphere structures was measured. The dye sensitized solar cell using nanoporous TiO2 as electrode materials exhibits an overall conversion efficiency of 7.36% with a light intensity of 100 mW/cm(2). The short circuit photocurrent (I-sc), open circuit photovoltage (V-oc), and conversion efficiency (eta) of these solar cells were improved over conventional materials.