Improved photovoltaic effect in CuO/Zn1-xMgxO heterojunction solar cell by pulsed laser deposition

In this study, the effect of Mg content in CuO/Zn1-xMgxO heterojunction thin films have been systematically investigated. This heterojunction was fabricated by Pulsed laser deposition on indium tin oxide covered glass substrate for solar application. The structural and optical properties of this heterostructure were analyzed by x-ray diffraction and ultraviolet-visible spectroscopy. The optical measurements reveal a shift in absorption edge and increase in transmittance with Mg content. Tuning of the band gap has been obtained from 3.28 to 3.5 eV corresponding to Mg content x varies from 0 to 0.10. An enhancement of open circuit voltage (V-oc) from 178 to 326 mV and short circuit current density (J(sc)) from 2.06 to 2.13 mA/cm(2) with the increase of Mg content was observed. It may be due to the conduction band of this heterojunction (CuO/Zn1-xMgxO) moving closer to vacuum level with increasing x. The maximum solar power conversion efficiency (eta=0.253%) was found with x=0.10. Hence, this improved solar power conversion efficiency in CuO/Zn1-xMgxO heterojunction makes this promising candidate for photovoltaic application. (C) 2016 Elsevier B.V. All rights reserved.