Germanium Quantum Dot Sensitized TiO2 Solar Cells
The size of Germanium (Ge) Quantum Dots (GQD’s) in Titanium Dioxide (TiO2) can be tailored, using different techniques like sputtering, laser ablation and sol gel. Similarly the absorption range of Ge may also be broadened in visible and NIR range. We report the use of Ge QD’s to sensitize meso-porous TiO2 film to make quantum dot sensitized solar cells (QDSSC) for the next generation photovoltaics. Ge -TiO2 nano-porous thin films were deposited using rf- planer magnetron sputtering using various ranges of rf-power, Argon pressure and substrate temperature. The fabricated films with various Ge concentrations were studied using X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), High Angle Annular Dark Field Imaging (HAADF) and UV-Visible Spectroscopy (UV-VIS).In the thin film meso-structure the Ge dots were embedded in the TiO2 matrix. The average particle size of Ge quantum dots was determined by HAADF. The solar cell performance has been checked using sun simulator. Experimental ways to improve cell performance are discussed.
Shaheed Khan, Iftikhar us Salam and Karim Ahmed
M. Abbas et al., "Germanium Quantum Dot Sensitized TiO2 Solar Cells", Key Engineering Materials, Vol. 442, pp. 404-414, 2010