Nanocrystalline ZnO Photoconductivity Measurements

Pure ZnO have been prepared on amorphous SiO2 substrates from a precursor solution of dihydrated zinc acetate and absolute alcohol. The sol was deposited on the substrates by the spin-coating technique. After de deposit of each layer, a drying treatment was performed at 200 °C for10 min, to solidify the deposited material. Finally, all the specimens were thermally treated at 450 °C for 3 h to crystallize them. The characterization by X rays diffraction was performed using the glancing angle configuration and films morphology was observed with an Atomic Force Microscope and by Field Emission Scanning Electron Microscopy. Photoconductivity was studied in function of the wavelength at 50 °C using the four-points method and illuminating by arrays of LEDs with different wavelengths.