Synthesis And Characterization Of Hybrid Metal Halide Perovskite Crystal

Hybrid metal halide perovskite materials are organic and inorganic complexes by molecular self-assembly process.And the process is easy and has low production cost,so halide perovskite materials can be used for large-scale industrial production and practical applications.The hybrid metal halide perovskite material not only has some properties of organic matter,but also has some properties of inorganic materials.On the molecular scale,it is organic-inorganic hybrid compounds,and a new hybrid metal halide materials,also has a unique quantum well structure,so the perovskite material also can be used as a light-emitting layer or the active layer of some devices,used for fabricating light emitting diode.The carrier mobility of the hybrid metal halide perovskite structure is higher,and the band gap can be adjusted.These advantages make perovskite structure materials have very important application prospect.In the research field of solar cells,light-emitting diodes,photodetectors and lasers,the hybrid metal halide perovskite has high potential.Hybrid metal halide perovskite structure based on the great application potential,we made further research on the method of synthesis of hybrid metal halide perovskite materials,explore the synthesis conditions of hybrid metal halide perovskite crystal and growth mechanism.In this work,a sequential deposition method named as MAI alcohol sealing method,is proposed.Firstly,PbBr2 layer is coated on FTO substrate.Secondly,the substrate is put into MAI alcohol solution.The solution is not only isolated from O2 and H2O,avoiding the perovskite decomposed in the forming process,but also the PbBr2 and MAI react completely.The as-prepared perovskite here is quite stable in atmosphere for relative long time and has high quality.And we compare the surface morphology characteristics and PL spectrum of the as-prepared perovskite,it is found that a proper concentration of DMF plays a crucial role in changing three-dimensional(3D)nanostructure to 1D nanostructure of perovskite single crystals.And a distinct red shift of the PL emission peak is found as the reaction time on account of the exchanges between I-ions and Br-ions in the perovskite crystal.We conclude that perovskite single crystals tend to 1D growth and form nanowire structures,but at the subsequent procedure of growth,because of the tetragonal structure of perovskite crystals,perovskite crystals start to grow in the other two dimensions,finally becoming nanosheets and micron-size crystals.