CsBi₃i₁₀ Perovskite:Synthesis And Optoelectronic Device Application

The research work of this dissertation is mainly focused on the synthesis of bismuth based lead-free all-inorganic perovskite materials.Combined with micro-nano processing,high performance optoelectronic devices are prepared.Through a series of means to achieve the improvement of material morphology and structure,and a series of characterization on the morphology and composition,along with the device assembly,the testing and optimization of photoelectric properties of the material are realized.The main contents of this dissertation are as follows:1.Preparation and surface treatment of Cs Bi3I10 perovskite thin films.The precursor solution of Cs Bi3I10 perovskite is synthesized by a simple and easy solution method,the precursor solution is spin-coated on a glass substrate,the antisolvent is added dropwise to promote the crystal precipitation,and to increase the film surface smoothness and crystallinity degree,vacuum assist the volatilization of solvent,and finally perovskite film material is obtained.In the process of material preparation,by selecting the appropriate anti-solvent and spin-coating rate,combined with vacuum means,the solvent in the precursor solution was volatilized at an appropriate rate.Through the characterization of the material's morphology,composition and optical properties,perovskite thin film material with high flatness and crystallinity is proved.The preparation method is simple,the raw material is non-toxic,the process requirement is low,and the cost is low,which makes it a possible substitution for the lead-based perovskite material.2.Preparation and testing of high performance red photodetector based on Cs Bi3I10 perovskite thin films.Through the micro-nano processing technology,a self-made mask is used on the surface of the film,and a red photoelectric detector with excellent photoelectric properties is successfully prepared by electron beam evaporation of the metal electrode.The performance of the device is optimizeb through the analysis of material structure and the selection of appropriate metal electrode.The Au / Cs Bi3I10/ Au photodetector has high switching ratio(up to 105),high response frequency(up to 2 k Hz),and outstanding response of up to 21.8 A / W,while the detection rate of 1.93 × 1013 Jones and the external quantum efficiency up to 4.13 × 103%.The performance of the device reaches and surpasses that of some lead-halogenated perovskite photodetectors,and at the same time,the device has high spectral selectivity and has good potential for photodetection.3.Preparation and performance testing of self-driven Si/Cs Bi3I10 heterojunction NIR detector.The built-in electric field in the Si/Cs Bi3I10 heterojunction photodetector effectively promotes the carrier separation and greatly improves the detection frequency,which can reach 2.5 times than that of the photoconductive photodetector.At the same time,the device has more obvious photovoltaic characteristics,it can work under zero bias and is self-driven,these features effectively expanding the application of the device,and can work more efficiently.The response of Si/Cs Bi3I10 based heterostructured perovskite photodetectors in the visible-near-infrared range further expands the application of the device.