The Research On Preparation And Properties Of Two-dimensional Organic-inorganic Hybrid （BA）₂Pb（I,Cl）₄ Perovskite Materials

Organic-inorganic hybrid perovskites have become the research hotspot for perovskite materials,due to their unique structures and good photoelectric properties.Two-dimensional organic-inorganic hybrid perovskite materials have larger adjustment space of performance than the three-dimensional materials,by changing the functional organic cations or increasing the thickness of perovskite layer,showing a good application prospect in solar photovoltaic cells,photodetectors and other fields.Compared with the three-dimensional structure,the two-dimensional organic-inorganic hybrid perovskite materials have the advantages of higher stability in the air and a larger adjustable band gap.As the low-cost light emitting device materials,two-dimensional hybrid perovskite materials with white light emission characteristics,also show the important application value in LED field.In this paper,for the first time,two-dimensional organo-inorganic hybrid perovskite materials with different halogen components are prepared,by using butylamine as the organic cation through adjusting the solvent system.And the influence of metal cadmium ions doping on the morphology and properties of the materials are also studied.The main research contents include as follows:（1）Butylammonium lead iodine（（BA）₂PbI₄）cross star thin sheets are synthesized via solution based method by using three kinds of solvents:N,N-Dimethylformamide（DMF）,chlorobenzene（CB）,and acetonitrile（ACN）.The effects of different ratios of the three solvents on the morphology of butylaminium lead iodine were studied.In the same ternary sovlent method,the rectangular films with uniform morphology are prepared by adjusting the ratio of solvents.The PL patterns show that the products have good white-light emission luminescence characteristics.（2）The effects of cadmium ions doping on the morphology of perovskite films are studied.The perovskite films(（BA）₂Pb_1-x-x Cd_xCl₄)with different cadmium doping amounts are prepared by liquid-phase reaction under relatively mild conditions.The results of XRD and SEM test show that the two-dimensional structure of the film is not affected by the doping of cadmium ions amounts.The PL test shows that cadmium ions doping can regulate the luminescence performance of perovskite,and the photoluminescence intensities change regularly with the increasing of cadmium ions doping amounts.（3）（BA）₂Pb_1-xCd_xCl₄ perovskite thin sheets with different doping amounts of cadmium ions are prepared by a ternary solvent method.Cadmium-doped（BA）₂Pb_1-xCd_xCl₄ thin sheets are prepared by adjusting the ratio of the three different solvents in liquid phase,the results of SEM and XRD show that（BA）₂Pb_1-xCd_xCl₄ thin sheets have the same optimal doping amounts as the films.In this paper,a ternary solvent method is developed for the liquid based preparation of（BA）₂Pb（I,Cl）₄ perovskite materials.The method shows good application in the synthesis of two-dimensional organic-inorganic hybrid perovskite.Through the study of cadmium doping on the structure and properties of butylaminium lead-chlorine film materials,it is shown that the two-dimensional（BA）₂PbCl₄ perovskite materials have good band gap tunability,which has certain significance for the practical application of two-dimensional perovskite materials.