Study On Preparation Technique For Perovskite Solar Cells With High Reproducibility And Large Area

Organic-inorganic hybrid halide perovskites have achieved a surging development in the field of photovoltaics for the advantages of simple fabrication process,low cost,strong absorption,and excellent carrier transportation.The perovskites solar cells exhibit remarkable photoelectric conversion efficiency,which have already achieved a record efficiency over 22.1%.However,it is still a long way to realize their industrialized application along the path,and more in-depth research works remained to be conducted.This work aims to develop cost-effective and suitable to scale-up manufacturing process for highly efficient perovskite solar cells,which covers aspects from perovskite film deposition improvement,device performance optimization to exploration of fabrication process of large-area perovskite film and perovskite solar cells.The specific contents and conclusions are as follows:(1)A multi-step spin-coating deposition process was proposed,in which a high concentration CH3NH3 I 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 CH3NH3 Pb I3 films both before and after the spin-coating of CH3NH3 I solution.Utilizing this multi-step spin-coating 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.(2)Through solvent engineering and combination of Cl additives,the perovskite film formation characteristic is optimized.It is found that within the DMSO solvent system,the addition of PbCl2 could significantly improve the quality of perovskite film and enhance its light absorption capacity.When the mole fraction of added PbCl2 is 30%,we get the optimized morphology,crystallinity and light absorption of perovskite film.Compared to the device without adding PbCl2,the efficiency of optimized perovskite solar cell reaches 14.42%,which is improved by 36.3%.(3)Perovskite film deposition method based on sputtering is proposed.Here,the Pb target with high purity is used to deposit PbO film with Ar as the protecting gas and O2 as the reacting gas.Then,the PbO film is converted to CH3NH3PbI3 by reacting with CH3NH3 I solution.Through optimization,we get perovskite film with ideal quality and excellent property.The efficiency of this perovskite film based mesoporous device reaches 13.8%.(4)By utilizing the sputtering perovskite deposition method,the industrialized fabrication of large-area perovskite solar cells is explored.Here,we achieve the device efficiency of 10.7% with the active area over 1 cm2.Also,the photovoltaic characteristics of perovskite solar cells with different active areas are compared and analyzed,which would provide beneficial reference for further investigation.