Study of antimony selenide hole-transport material for Mo/Sb2Se3/MAPbI3/C60/GZO/Ag heterojunction planar solar cells

Antimony selenide (Sb2Se3) photovoltaic exhibits low energy band gap for effective wide solar spectrum utilization. A new heterojunction planar solar cell design has been investigated using thin Sb2Se3 hole-transporting material (HTM) layer between bi-layer molybdenum (Mo) electrode and CH3NH3PbI3 (MAPbI3) perovskite active absorbing layer. The solar cell structure was prepared as Mo/Sb2Se3/MAPbI3/C60/GZO/Ag on fluorine-doped tin oxide-coated glass substrate. Thus, the HTM layer, active absorbing layer, electron-transporting layer, transparent conductive oxide layer, and top electrode contact layer, has been made of Sb2Se3, MAPbI3, C60, gallium-doped zinc oxide, and silver, respectively. The Sb2Se3 HTM layers were also annealed at different temperatures of 300–600 °C. Scanning electron microscopy study showed improved crystal grains with the annealing temperature. This new heterojunction planar solar cell exhibited high power-conversion efficiency of 16.8% with the 200 nm Sb2Se3 HTM layer that was annealed at 600 °C. The device corresponding VOC, JSC, FF, Rs, and Pmax had been 1.07 V, 20.7 mA/cm2, 75.8%, 18.6 Ω, and 1.68 mW, respectively. •New heterojunction planar solar cell of Mo/Sb2Se3/MAPbI3/C60/GZO/Ag has been fabricated.•Sb2Se3 HTM layer was prepared between bi-layer Mo electrode and solution-processed MAPbI3 active absorbing layer.•Photovoltaic characteristics investigated at various film thicknesses and annealing temperatures•Power-conversion efficiency was improved from 13.5% to 16.8%.•VOC, JSC, FF, Rs, and Pmax at 1.07 V, 20.7 mA/cm2, 75.8%, 18.6 Ω, and 1.68 mW, respectively.