Nano-semiconductor Material Preparation And Devices

Two-dimensional?2D?nanomaterials have been widely concerned by researchers since graphene was fabricated in 2004.Compared with bulk materials,2D materials can display extraordinary properties in many fields because of its unique structure.Today monolayers of various types of layered materials can be synthesized by using bottom-up and top-down approaches,even unprecedented physicochemical properties can be engineering by controlling the number of layers of 2D materials.The use of graphene in electronics and photo electronics was restricted because that graphene is zero band gap material and it is complex to open its band gap.2D semiconductor,especially 2D layered metal dichalcogenides were ideal alternative materials in the next generation of electronics and photo electronics.2D layered metal dichalcogenides with the general formula of YX₂ is formed by a metal atom?Mo,W,Ga,Sn,etc.?sandwiched between two chalcogen layers?S,Se,Te?.SnS₂ is a member of 2D MDCs semiconductors with hexagonal CdI₂ type crystal structure?a=0.3648 nm,c=0.5899 nm,space group P m1?and indirect band gap of 2.2 eV.In recent studies,SnS₂have exhibited good performance in many filed such as lithium ion batteries,visible-light-driven photocatalyst,field-effect transistors,sensors,photodetector.Especially when SnS₂ nanoflakes used as photodetector,it shows superior performance such as fast response rate,high on/off ration and good stability.Furthermore,SnS₂,as an earth-abundant and environment-friendly material,is promising for practical or commercial application.From the above,finding a way to fabricated SnS₂ with high efficiency and quality is significant.Here,we will introduce the work about SnS₂ from three section.First of all,the fabrication of SnS₂.By precise control four temperature zones respectively,a high-efficiency method was introduced to fabricated SnS₂ crystal with high quality.Secondly,dispersed SnS₂ crystal on SiO₂/Si and fabricated it to bake gate filed effect transistorviacoating-electronbeamlithography-development-photographic fixing-electrode evaporation-lift off.And then detection and analysis its electrical properties.At last,use the SnS₂-based photodetector to detect light??=405nm?.The photodetector shows fast response rates?rising time of 0.4 ms and falling time of 0.56ms?,low dark current,high responsivity and detectivity.Furthermore,explore the ways to improve the performance of SnS₂ photodetector.