PERFORMANCE OF DYE SENSITIZED SOLAR CELLS FABRICATED FROM OBLIQUELY DC SPUTTERED TiO2 FILMS

Abstract

- Nanocrystalline porous titanium oxide films of varying thickness have been deposited in ambient by reactive DC magnetron sputtering at a fixed but high oblique angle of 60o, and then converted to TiO2 by thermal annealing at 450 oC for 4 hours. X-ray diffraction analysis of the films showed that they were predominantly of anatase phase, whereas the as-deposited films were amorphous. Top–down scanning electron microscope images of the annealed films showed cauliflower-like surfaces, and exhibited well-defined columns. Atomic force microscope images revealed rough surfaces with larger nodules for thicker films. With the annealed films as the working electrodes in a dye-sensitised solar cell, it was established that the photoelectric conversion efficiency increased with the film thickness. The highest efficiency was ~ 3.3 % at an illumination intensity of 100 W/m2.