Planar perovskite FAxMA1-xPbI3 solar cell by two-step deposition method in air ambient

Perovskite material presents prospective application potential in the third generation solar cell for their broad spectral absorption, small exciton binding energy and long exciton diffusion length. In this paper, low temperature and stable mixed-cation perovskite FAxMA1-xPbI3 solar cells fabrication method in air ambient was reported. The inverted planar ITO/PEDOT:PSS/FAxMA1-xPbI3/PCBM/Ag structure was fabricated in air ambient, which shows better performance than either FAPbI3 or MAPbI3 devices, and FA0.4MA0.6PbI3 demonstrates the highest PCE of 9.7% among the FAxMA1-xPbI3 solar cell devices. In order to decrease the potential barrier between the PCBM and Ag electrode, a layer of Bphen was inserted between PCBM and Ag electrode, the PCE of ITO/PEDOT:PSS/FAxMA1-xPbI3/PCBM/Bphen/Ag perovskite solar cell was increased to 10.86%. We simulated and calculated the absorption and band energy of perovskite materials to verify the accuracy of experimental results. Our result provides a progress towards fabricating perovskite solar cells in the air ambient.