Magnetron sputtering fabrication and photoelectric properties of WSe2 film solar cell device

Tungsten diselenide (WSe2) films with different growing orientations exhibit diverse photoelectric properties. The WSe2 film with C-axis perpendicular to substrate texture has been prepared and applied to thin-film solar cells. W nanofilms with a thickness of 270 nm were deposited onto the Mo bottom electrode and then heat-treated in selenium vapor to synthesize WSe2 films with a thickness of 1 mu m. ZnO films were deposited onto WSe2 films to form a P-N junction and ITO films were deposited subsequently as the conductive layer. X-ray diffractometry, scanning electron microscopy and UV-vis-NIR spectro-analysis instrument were employed to analyze the phase composition, optical absorptivity and micromorphology of WSe2 films and the WSe2 solar cell device. WSe2 films exhibit excellent photoelectric performance with an optical absorption coefficient greater than 105 cm(-1) across the visible spectrum. The calculated direct and indirect band gap of the WSe2 films is 1.48 eV and 1.25 eV, respectively. With the application of standard glass/Mo/WSe2/ZnO/ITO/Ag device structure, the open-circuit voltage of the battery device is 82 mV. The short-circuit current density is 2.98 mA/cm(2) and the filling factor is 0.32. The photoelectric conversion efficiency of the WSe2 film solar cell device is 0.79%. (C) 2018 Elsevier B.V. All rights reserved.