Improved efficiency of perovskite solar cells based on Ni-doped ZnO nanorod arrays and Li salt-doped P3HT layer for charge collection

We demonstrate regular-type perovskite solar cells based on vertically grown Nidoped ZnO nanorod arrays and doped P3HT for solar energy harvesting. PCBM was introduced between Ni-doped ZnO nanorod arrays and the perovskite layer to improve electron extraction, while P3HT doped with bis(trifluoromethane)sulfonimide lithium salt (Li- TFSI) was used as hole transporting layer. Three types of perovskite materials, including MAPbI₃, (MA)_x(FA)_1-xPbI₃, and (MA)y(GA)_1-yPbI₃, were used as light harvesting layers to exploit conversion efficiency of photovoltaic devices. The optimized perovskite solar cell with the configuration of ITO/Ni-doped ZnO nanorods/PCBM/(MA)_y(GA)_1-yPbI₃/P3HT + Li- TFSI/Au revealed an open-circuit voltage of 0.83 V, a short-circuit current density of 23.73 mA/cm², a fill factor of 70%, and a power conversion efficiency of 13.79%.