High reproducibility of perovskite solar cells via a complete spin-coating sequential solution deposition process

• A complete spin-coating sequential solution deposition process was proposed.
• Spin-coating of pristine isopropanol has important significance in CH3NH3PbI3 films.
• The reproducibility of perovskite solar cells was significantly improved.

The controllability of conditions and parameters, in a certain procedure that adopted to prepare perovskite absorption layer, play a crucial role in morphology and crystallization of the resulting films, which is of great impact on the reproducibility of solar cells. Here we propose a complete spin-coating sequential solution deposition (spinning-SSD) process, in which a high concentration CH3NH3I precursor was spin-coated on PbI2-coated substrate insteading of immersing procedure; the pristine isopropanol was spin-coated to ameliorate the surface morphology and improve the quality of the resulting CH3NH3PbI3 films both before and after the spin-coating of CH3NH3I solution. Utilizing this spinning-SSD process, we fabricated meso-structured perovskite solar cells, and these devices exhibited decent performance and high reproducibility, achieving an average power conversion efficiency of 11.3% with the standard deviation as low as ±0.52. This optimized approach is expected to be used for fabricating high-performance perovskites solar cells with a full printable process.