First Principle Molecular Dynamics Study Of CsPbBr₃ Nanosheets And PbSe Quantum Dots

With the development of science and technology in the 21 century,sensors are widely used in the unmanned aerial vehicle?UAV?,infrared imagery,missile guidance and so on.Perovskite of inorganic lead halogen has become one of the hotspots of research because of its high quantum conversion efficiency,wide wavelength coverage and narrow half-height.As inorganic lead-halide perovskite,CsPbBr₃ nanomaterials were less studied in Preparation,basic properties,formation mechanism and quantum dot recombination.In this paper,the basic parameters of hexagonal CsPbBr₃ perovskite,surface energy,adsorption energy and the photoelectric properties of PbSe quantum dots were studied based on first principle and molecular dynamics.The size and performance of CsPbBr₃ unit cells under different optimization functions were compared by Materials Studio software in this acticle.Based on the hexagonal morphology nanocrystals prepared in the laboratory and the experimental results,the two Miller index surfaces?100?and?110?of perovskite nanoparticles were analyzed in the simulation process.In order to verify this phenomenon from thermodynamics and kinetics,the surface energy and adsorption energy of the two surfaces were analyzed in the experiment.To remove the polarity of?110?surfaces,we deleted atoms from different terminating surfaces in the calculation of surface energy.Physical adsorption and chemisorption were used to calculate the adsorption process.At the end of this paper,the basic characteristics of quantum dot PbSe were simulated.The PbSe?100?plane and the CsPbBr₃?100?plane,which have higher lattice matching degree were used to construct the layered composite structure.The band gap and optical spectrum of the CsPbBr₃ layer,which combined with the PbSe layer were compared experimentally.The performance changes caused by the composite heterojunction were also observed.This article takes the photoelectric sensor as the application background.Based on the controllable Chemical Synthesis of Inorganic lead Halide perovskite,we have studied the surface energy,adsorption energy and the effects of various properties on the growth of the synthesized perovskite nanocrystals,as well as the performance changes and potential applications caused by PbSe quantum dots and perovskite.Firstly,it is found that CsPbBr₃perovskite of inorganic lead halogen is a good direct band-gap semiconductor by simulation.Secondly,the?110?surface of perovskite with large scale hexagonal morphology has large surface energy.However,oleic acid has strong adsorption energy on the surface,which reduces the growth rate of the surface.Finally,the optical properties of CsPbBr₃ nanosheets are strengthened and the electronic band gap is amplified after combined with PbSe.In a word,it has some guiding significance for the development of inorganic lead halogen perovskite photoelectric sensor.