Preparation Of Graphene/RbAg₄I₅ Composite Nanostructures And Their Photoelectric Properties

In 2010,the Nobel Prize in Physics was awarded to graphene discoverers Andre Geim and Konstantin Novoselov,who used the simplest mechanical exfoliation method to produce the magic material,which exists at theoretically absolute zero temperature,under normal conditions.Since then,scientists around the world have devoted themselves to the research of various two-dimensional nanomaterials.Graphene,a two-dimensional nanomaterial composed of just one layer of carbon atoms,is an ideal quasi-two-dimensional electronic gas.As a zero-bandgap semiconductor,its special band structure enables it to have extremely excellent physical and chemical properties in electrical,optical,and other aspects,and it is considered as the most promising next-generation photoelectronic material to replace silicon semiconductor,which has great research value in theory and practice.In the past decade,a lot of remarkable work has been done in graphene research?Chapter 1?.In many works,the research on graphene-based optoelectronic devices mainly develops in two directions:one is to make full use of the ultra-high carrier mobility in graphene to develop ultra-fast graphene optoelectronic devices;the other is to improve the photoabsorption of graphene,so as to develop graphene photoelectronic devices with higher sensitivity and detectivity.Both two directions have very outstanding research results.However,there are some problems:for the ultra-fast response graphene optoelectronic devices,the carrier life is short,so that its responsivity is not high;for the ultra-high response graphene optoelectronic devices,the carrier recombination is slow,which seriously affects the response speed.Therefore,in the field of further developing graphene photodetectors with excellent response characteristics such as ultra-sensitive,ultra-fast and broadband detection,the prospect can be expected while the journey is long and challengeable.This paper will combine graphene with superionic conductor RbAg₄I₅ to explore the feasibility of realizing ultra-sensitive and ultra-fast photoelectric detection by means of ion regulation of electron transport in graphene.In this paper,the composite nanostructures based on single-layer graphene?Chapter 3?,multi-layer graphene?Chapter 4?,PMMA-assisted suspended graphene?Chapter 5?and RbAg₄I₅ thin films were studied successively,and the preparation and characterization methods of composite nanostructures and their photoresponse characteristics were systematically studied.In aspects of experiment,it realizes the photoelectric performances with high responsivity(?1 A·W^-1),fast response speed??10²?s?and wide detection wavelength range?ultraviolet to near-infrared?.In terms of theory,we proposed a photoelectric dynamic response model with the dissociation and recombination process of"electron-ion bound states"?IEBSs?as the basic physical image.The model and the further modified model can successfully explain the experimental phenomena,and the fitting the results given by the dynamic equation are quite coincident with experimental statistical data.In conclusion,although graphene/RbAg₄I₅ composite nanostructure has some shortcomings in the application of photoelectric detection,its excellent response performance has shown considerable application potential.This provides a new idea for the development of graphene-based optoelectronic devices and a meaningful reference for the further exploration of ion modulated devices.