Study On Perovskite Micro-nano Array Photodetector

Perovskite,as an emerging excellent semiconductor material,is widely used in photodetection,laser,photovoltaic,and radiation detection,etc.Compared with the polycrystalline perovskite film and microcrystals,the single crystal perovskite devices produced by the single crystal perovskite usually have more excellent photoelectric performance.However,the main challenge for the micro-nano processing of perovskite is that the preparation of structural arrays for halide perovskite functional nanomaterials has not yet achieved low-cost,large-area,controllable high-quality one-dimensional micro-nano single crystal perovskite with the solution method.A unique technical means-infiltration controllable induction assembly technology is used in the laboratory by modifying the micro-pillars,changing the surface infiltration,controlling the crystal growth position and growth direction,and it has achieved large area,low cost,high efficiency,high precision and high crystallinity,and studied the performance of optoelectronic devices prepared with micro-nano structure arrays.The main results are summarized as follows:The key to the research is to create asymmetric wettability interfaces for directionally dividing the continuous liquid film.Driven by the Laplace pressure,the vertical dewetting of capillary flows between adjacent interfaces facilitates the formation of capillary bridges with the uniform size and shape to support the 1D confinement of crystallization.On the modified elongated silicon column template,according to different perovskite materials such as Cs Pb Br₃,MAPb Br₃,FAPb Br₃,templates of different widths is chosen to prepare a longitudinal capillary liquid bridge array,by adjusting the concentration of the precursor solution and the solvent of the precursor solution to control the direction and position of the liquid nucleation.single crystal perovskite FAPb Br₃ array characterized by fluorescence microscopy,scanning electron microscopy,transmission electron microscopy,etc.The prepared single crystal microwire array trap density is3.38×10¹³cm^-3,the life span is more than 200 ns.Further preparation of the photodetector showed a bright-dark current ratio of 10^4,reaching a responsiveness of 3 AW^-1.