A comparative study of different M(M = Al, Ag, Cu)/FTO bilayer composite films irradiated with nanosecond pulsed laser

Aluminium (Al), silver (Ag) and copper (Cu) layers were deposited on commercial fluorine-doped tin oxide (FTO) glass by direct current (DC) magnetron sputtering, so as to form Al/FTO, Ag/FTO and Cu/FTO bilayer films. Then all the as-deposited metal/FTO films were irradiated using a 532 nm nanosecond pulsed laser with a fluences of 1.05 J/cm(2). X-ray diffraction (XRD) analysis confirmed that all the laser-irradiated films were annealed by the laser and showed increased average crystallite size in FTO layers. Laser-induced grating structures were also obtained on the surfaces of the laser-irradiated Ag/FTO and Cu/FTO films, resulting in higher surface roughnesses and average transmittances of the films. But due to the broken continuity of the Ag and Cu layers, the sheet resistances of these two films slightly decreased as compared to that of the laser-irradiated Al/FTO film. It was also found that the laser-irradiated Ag/FTO film, whose average transmittance in 400-800 nm waveband and sheet resistance was 81.5% and 6.6 Omega/sq respectively, had the better figure of merit, indicating that the photoelectric property of FTO-based bilayer films could be further optimized through achieving fabrication of laser-induced grating structures and laser annealing in one step. (C) 2014 Elsevier B.V. All rights reserved.