Large area dye-sensitized solar cells: Material aspects of fabrication

Dye-sensitized photoelectrochemical solar cells of large area are fabricated using highly conducting and optically transparent glass consisting of an inner layer of indium-tin oxide and an outer layer of fluorine doped tin oxide. A method is described for the deposition of nanocrystalline films of TiO₂ consisting of large and small median size particles (30 and 5 nm, respectively) which promote porosity and light scattering. Incorporation of trace quantities of magnesium oxide into TiO₂ increased the efficiency of the cells. The energy conversion efficiency of a cell (AM 1.5, 1000 Wm^-2 simulated sunlight) of area 21 cm² was found to be 7.2% compared to 5.6% in the absence of magnesium oxide. The mechanisms by which the magnesium oxide improves the cell performance are discussed.