Electrodeposition of ZnO nanorod arrays for application in perovskite based solar cells

Abstract

We report a low-cost, free-hole conductor methylammonium lead iodide CH3NH3PbI3 (perovskite)/ZnO nanorods (NR) heterojunction solar cell. ZnO nanorod arrays were obtained electrochemically onto transparent conducting oxide (fluor doped tin oxide, FTO) from an aqueous solution of zinc acetate. The ZnO NR were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical transmittance. Solar cell was fabricated forming the perovskite material onto the ZnO thin flm. Spin coating of an equimolar mixture of CH3NH3I and PbI2 in γ-butyrolactone solution (perovskite precursor solution) leads to CH3NH3PbI3 formation on ZnO NR. A graphite-covered FTO/glass was used as a back contact. The photovoltaic performance of the solar cell was characterized at full sun intensity of 100 mW/cm2 obtaining a shortcircuit current of 1.5 mA/cm2, an open circuit voltage of 0.47 V and energy conversion efficiency of 0.16 %.