Fabrication And Properties Of Solution Processed Perovskite Solar Cells

Organometal halide perovskite solar cells have become a hotspot among the researchers due to their excellent optoelectronic properties,easy fabrication and low cost.The efficiency has increased from 3.8%to 20.1%,which indicates a good application prospect.At present,researches about perovskite solar cells are mainly focused on film quality improvement of perovskite active layer and interface modification.In this study,we conducted researches on the low temperature solution processed perovskite solar cells and their performance,which lay the foundation for realizinghigh-throughput"roll to roll" preparation.Contents and conclusions of this article are as follows:For conventional structure perovskite solar cells,CH3NH3PbI3 perovskite was grown as active layer via two step spin coating technology and a low temperature processed ZnO electron transport layer was introduced to avoid the hightemperature sintering process of mesoporous structure.The device structure is ITO/ZnO/CH3NH3Pbl3/spiro-OMeTAD/Ag.The as prepared perovskite layer showed great crystalline quality and the cuboids were uniformly distributed with good surface coverage.The optimum thickness of ZnO layer in the device was investegated and the results indicated that the device showed the best performance with ZnO thickness of 25 nm.Besides,all solution processed perovskite solar cells were achieved by employing spray-coated silver nanowires as the top electrode,the device showed great reproducibility and exhibited the highest power conversion efficiency of 9.21%with shortcircuit current density of 19.75 mA/cm2,open circuit voltage of 1.02 V,and fill factor value of 0.457.For inverted structure perovskite solar cells,one step solution processed CH3NH3PbI3_xClx was introduced as the active layer.The device structure is ITO/PEDOT:PSS/CH3NH3PbI3-xClx/PC61BM/Ag.Effects of different preparation parameters for the device performance were studied,the results indicated that the perovskite layer was well-crystallized and the device showed best performance with power conversion efficiency of 10.16%when the perovskite precursor solution was spin coated at 4000 rpm and annealed at 100 ℃ for 120 min.To further improve the device performance,gold nanoparticles(AuNPs)were doped into PEDOT:PSS for anode modification,which improved the interface and surface morphology of perovskite layer and increased the light absorption.The results indicated that when PEDOT:PSS and AuNPs were mixed with a volume ratio of 3:1,the device performance showed great improvement and exhibited a power conversion efficiency of 11.51%with shortcircuit current density of 19.27 mA/cm2,open circuit voltage of 0.93 V,and fill factor value of 0.641.In conclusion,device structures and preparation technologies for conventional and inverted structure perovskite solar cells were systematically studied,and good photovoltaic performance were achieved,thus this work has a certain reference significance for "roll to roll" preparation of perovskite solar cells.