Two-dimensional ABX₃ Perovskite Single Crystal For Photodetector

Recently,ABX₃ perovskite single crystals have become the hotspot of photodetector research because of its low density of trap states,high carrier mobility and long diffusion length.However,the organic-inorganic hybrid perovskite single crystals are so fragile that the single crystal perovskite sheets with a thinner thickness(<100 um)are hardly obtained by cutting bulk into sheets.Therefore,the direct preparation of micrometer thickness perovskite single crystal is great significance for the further development.In this paper,the growth conditions of perovskite single crystals were studied and the methods of"liquid-liquid interface confinement"and"double flexible interface confinement"were developed,and the MAPbCl₃?MAPbBr₃?MAPbB₃-MAPbCl₃ heterostructured single crystal photodetectors were prepared to obtain excellent photoelectric conversion performance.The research content is as follows:1.A new single crystal growth method,namely"liquid-liquid interface limiting method",is proposed for the synthesis of 2D MAPBBr₃/MAPBCl₃ perovskite single crystals.Compared with the traditional space limiting method,our method use liquid-liquid interface to limit the thickness of the crystal and improve the crystal quality.In addition,the method were extended to the growth of MAPbBr₃ crystal,which can be prepared at 0?,further reduces the defects of the device and improves the performance.2.By combining the"liquid-liquid interface limiting method"described above,MAPbBr₃ precursor solution was added to the grown MAPbCl₃ crystal after concentration regulation.After the in-situ growth of MAPbBr₃,the MAPbB₃-MAPbCl₃heterostructured single crystals with micron thickness was obtained.And its physical and photoelectric properties were analyzed.3.For large-scale preparation of perovskite crystal with micron thickness,we put forward the"double flexible interface limited domain method"to synthesizes perovskite crystals.Using polyethylene film as the limited domain substrate,the permeability of the film is used to improve the saturation of the solution by diffusion,and the crystal quality is improved.The photoelectric performance of a single crystal photodetector is analyzed,which proves the feasibility of the method.The photoelectric performance of single crystal photodetector is analyzed and the feasibility of this method is proved.