Investigation Of PEA₂CuBr₄/FASnI₃ Perovskite Solar Cell

The photoelectric conversion of organic-inorganic hybrid lead-based perovskite solar cell have exceeded 23%within a few years.However,the toxic of lead?Pb?in their structure limits its further application.Tin?Sn?-based perovskite material is brought up as a promising substitute for the lead-based material due to their similar optical and electronic properties,and the tin-based perovskite solar cell does no biological and environmental harm.The most concerned drawback regarding tin-based material is its low stability and susceptibility to oxidation at present.To address this problem,this paper proposes a combined two dimensional-three dimensional?2D-3D?structure,PEA₂CuBr₄/FASnI₃?Cu/Sn-based?perovskite material design–synthesized from two-dimensional copper-based perovskite material(PEA₂CuBr₄)and tin-based perovskite(FASnI₃).We look into the basic properties and the stability of this material,and applied it to the inverted planar structure of the solar cell device in order to study its photoelectric conversion performance.The main contents of this paper are as followed:?1?The preparation and characterization of Cu/Sn based perovskite material.Preparation of different proportions of Cu/Sn-based perovskite films by spin coating the precursor solutions.X-ray diffraction?XRD?,Energy Dispersive Spectrometer?EDS?,X-ray Photoelectron Spectroscopy?XPS?,UV-Visible absorption spectrum?UV-Vis?,Scanning electron microscope?SEM?and other characterization methods were used to analyze its structure and composition,optical properties and surface morphology.Effects of different Cu/Sn ratios on the properties of perovskite material were studied,the best ratio was selected as Cu/Sn?1.5%?.Compared with the pure FASnI₃ perovskite material,the Cu/Sn?1.5%?perovskite film has better crystallinity,more uniform crystal orientation,higher light absorption,larger optical band gap,and better surface morphology.?2?Research on stability of Cu/Sn-based perovskite material.The thermal stability,humid stability and oxidation resistance of Cu/Sn?1.5%?perovskite material were investigated.Results show that Cu/Sn?1.5%?perovskite films didn't decompose at 120?after heating for 15 hours.No obvious degradation occurred after 12 hours in the atmosphere with humidity over 70%.The ratio of Sn²⁺/Sn⁴⁺was 0.28.The addition of PEA₂CuBr₄ effectively improved thermal and humid stability of perovskite material,and inhibited the oxidation of Sn²⁺.?3?Study on the performance of Cu/Sn-based perovskite solar cells'device.Inverted planar structure solar cell devices are prepared using different Cu/Sn ratio hybrid perovskite thin films as absorbent layers.The photovoltaic performances of the devices are tested.The addition of two-dimensional perovskite improves the stability of the device.Results showed that the Cu/Sn?1.5%?perovskite solar cell's photoelectron conversion was 6.5%,which was about twice as much as a pure FASnI₃battery device.The addition of Cu-based two-dimensional perovskite can effectively realize defect passivation,inhibit defect auxiliary carrier compound and improve the mobility of hole carriers.So that the dark current and hysteresis effect of battery devices were reduced,and battery's performance was improved.The Cu/Sn?1.5%?solar cell device maintained the photoelectron conversion still over 90%of its best efficiency after stored in a nitrogen?N2?filled glovebox for more than 40 days.