Photoconductivity of Copper (I) Iodide (CuI) thin films for dye-sensitized solar cells

The work presented here shows the effect of annealing temperature on CuI thin films. The 0.05 mol of CuI solution is prepared at room temperature and then deposited in silicon and glass substrate. The CuI thin films were deposited using sol-gel spin coating method. The electrical, optical properties and surface morphology was characterized by current-voltage (I-V) measurement, ultraviolet-visible (UV-VIS) measurement and Field Emission Scanning Electron Microscopy (FESEM) respectively. The I-V measurement in dark indicates that the resistivity decreases until the sintering temperature is ~100°C. However, the resistivity of CuI under illumination is increasing since CuI tends to be oxidized under continuous illumination. These films exhibited an optical transmittance of 47%-80% at various annealing temperature in the wavelength of 400-800nm.