Studies Of Perovskite On Preparation And Optoelectronic Properties

Recently,organic-inorganic halide perovskites are favored as optoelectronics materials.These halide materials consist of metal-halogen atoms as octahedral framework and organic cations as filler.Perovskites are becoming popular materials in solar cells for their high carrier density,long diffuse length,low auger recombination rate and suitable energy gap.The photoelectric conversion efficiency increases from 3% to over 20% in just a few years,showing its unique superiority in this field.Meanwhile,due to the characteristic of halide material,band engineering of perovskites by adjusting the proportion of elements is widely studied,leading to the wide use in luminescent devices.By now,perovskite quantum dots are paid great expectation in light emitting diodes and displays for their high quantum efficiency and ease of mass production.In despite of the wide application prospects,however,perovskites are facing challenge.For example,the poor stability and hysteresis in current–voltage characteristic curve restrict the further development in optoelectronic devices.In addition,the efficiency of light emitting diodes based on perovskite is still much lower than that of conventional semiconductor materials.Another trouble of perovskites is the environmental pollution owning to the lead element in most halide perovskite materials.Although lead can be replaced by other elements,the optoelectronic performance is not as good as lead halide perovskites.At the same time,the mechanism of photon-electron conversion is far from clear.Many phenomena have no certain conclusions,which further restrict the potential use of perovskite materials.In conclusion,many methods are expected to use to solve these principle problems.The optoelectronic properties are essentially the production and recombination of photon-generated carriers,accompanied by the absorption and emission of light.Therefore,we can use spectrum analysis to investigate the production and recombination process of photon-generated carriers in semiconductor materials.In this paper,we first synthesize MAPbBr₃ micro crystals by aqueous crystallization.Then we investigate their luminescent properties and related carrier dynamic,light-matter interaction.The main researches are shown as below:1.Introduction of basic properties and synthesize methods of perovskites,including their applications and optoelectronic properties,i.e.,photovoltaic and luminescence property.2.Synthetization of MAPbBr₃ micro wires and micro plates by aqueous crystallization.Investigation of growth morphology affected by substrate and solution concentration.Characterization of their morphology and structure.Introduction of characterization methods and principles in this paper.3.The formation and recombination of carriers of MAPbBr₃ perovskites investigated by photoluminescence spectrum,absorption spectrum and time-resolved photoluminescence spectrum.In addition,we also study the properties of stimulated radiation,e.g.,laser modes,threshold,and polarization.4.Waveguide properties and light matter interaction in MAPbBr₃ microcavity investigated by spatial resolved photoluminescence and numerical simulation.The strong couple of photon and exciton in perovskite microcavity described by Lorentz exciton-polariton model.The effect of mode volume and excitation intensity to photon-exciton couple strength.