The Size Of The Graphene Control Research

Graphene, also called graphite nanoplatelet, is a newly developed material withsingle atomic layer structure. It is a two dimensional material with hexagonal crystallattice. Because of its unique structure, it has quite a lot of unusual properties, such asgood thermal conductivity, excellent electrical conductivity and high aspect ratio (ratioof lateral size to thickness), which makes it full of potential for field emission. So,graphene has gained much attention by the scientists all over the world and has apromising future.SED, which is the abbreviation for surface conduction emitter display, is a part ofFED. Recently it has become a hottest topic among the display devices with itssuperiority of high brightness and resolution. The electron emitters, which launchelectrons and stimulate the screen, are made based on the theory of surface conductionemission.As the surface conduction emission can be defined as a two-dimensional emission,also grapheme is a two-dimensional material which has perfect capability of electronemission, so we decide to use grapheme as the emitter of SED.We have observed from the research that the properties of graphene greatly dependon the structural characteristic, for example, its electric characteristic will changeobviously if the number of layers changes. Therefore, to explore how to control thestructure of grapheme is significant to the fundamental study and application devices inthe future.In this paper, we have studied the preparation principle of grapheme and discussedthe possibility of using grapheme in the SED. The main content are as follows:1. We have scientifically studied two ways of preparing graphene with differentstarting materials. Dialys have been used to improve the process of removing acid andgreatly increased the efficiency of our experiment.2. The number of layers has been controlled in the way of selecting differentstarting materials with three steps of oxidation, thermal expansion/exfoliation,reduction and dispersion. Through differential centrifugation, we have succeed in controlling the size of the prepared grapheme. Then we can say we have controlled thestructure of grapheme.3.FED screen have been obtained by means of electrophoresis, compared with thescreen prepared by gravitational settling, we find it more uniform, compact than thatmade by gravitational settling, also it has higher brightness. Furthermore, the success ofthe preparation of FED screen has laid a foundation for the grapheme’s SED structure.