| In recent years,with extensive use of two-dimensional materials,more and more two-dimensional materials were found and studied by scientists.Among which,gallium selenide,on behalf of IIIA-VIA chalcogen compounds,approached to the scene view of human gradually.Two-dimensional(2D)GaSe nanomaterials with unique properties like photoelectricity,thermal,light response,and nonlinear optics,have been widely applied in solar cells,photodetectors,flexible electronics,nonlinear optics and many other fields.Therefore,how to prepare excellent few-layer/single-layer GaSe nanomaterials simply and efficiently has become a topic of concern to many scientific researchers.In this paper,the liquid phase exfoliation(LPE)method is adopted.Through the design and analysis of orthogonal experiments and single factor experiments,the priority and optimal process parameters of the three factors of ultrasonic temperature,centrifugal speed and GaSe solution concentration in the liquid phase peeling process are determined.And successfully prepared a few layer/single layer two-dimensional GaSe nanomaterials under the optimal process parameters.In order to verify the electrical characteristics of the obtained two-dimensional GaSe material,a preliminary p-GaSe/n-SiPN junction prototype structure was designed and its volt-ampere characteristic curve and time response performance under different illumination conditions were studied.The main research contents of this article are:1.Using bulk GaSe materials and isopropanol solution as raw materials to design six sets of control experiments with LPE method.The samples were characterized by four methods:Metallographic Micrographs,Atomic Force Microscopy,Raman Spectroscopy and Photoluminescence Spectroscopy.By exploring the relationship between sample thickness and characterization results,come to a conclusion that the thinner the sample,the lighter color of the peeled off two-dimensional GaSe nanomaterial will be.With sample thickness decrease,the peak intensity of the vibration peak of the Raman Spectrum will gradually decrease even disappear,also the peak position of the photoluminescence peak will appear blue shift and the peak intensity will decrease.2.Design a three-factor and five-level orthogonal experiment to prepared 25 samples and than based on the photoluminescence peak intensity of the sample measured at room temperature and combine with the Metallographic Micrograph,Raman Spectrum and Photoluminescence Spectrum of the two-dimensional of GaSe material to perform range and variance analysis.The results of range and variance indicated that the primary and secondary order of the three factors is: ultrasonic temperature>centrifugal speed>GaSe solution concentration.On the basis of orthogonal experiments,combined with single factor experiments,the optimal process parameters for preparing a few layers/single layer two-dimensional GaSe materials were: ultrasonic temperature=40 ℃,centrifugal speed=10000 rpm,GaSe solution concentration =25 mg/ml.Then use XRD,Metallographic Micrographs,EDS,Raman Spectroscopy,TEM,HRTEM,SAED,AFM,Photoluminescence Spectroscopy to characterize and analyze the samples made according to optimized process parameters.It shows that the single-layer GaSe materials were made successfully.3.In order to verify the electrical properties of the prepared two-dimensional GaSe material,this paper designs a preliminary p-GaSe/n-SiPN junction prototype structure,with the few-layer/single-layer two-dimensional GaSe nanomaterials prepared under optimized process parameters,drip-coate and made the preliminary p-GaSe/n-SiPN junction successfully.Test the volt-ampere characteristic curve and time response curve under different wavelengths and different optical powers.Identify that the PN junction has the best performance at a wavelength of 405 nm,the corresponding light response intensity is 75 mA/W,the external quantum efficiency is 25% with the extremely short response time. |
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