Preparation Of Graphene Based Composite Materials And Its Application In The Field Of Optoelectronic Information Storage

Graphene is a 2D crystal which formed by sp2 hybrid carbon atoms in hexagonal lattice with an only one atom layer thickness. Because of its unique two-dimensional structure, graphene has a special energy band structure and ultra high carrier transmission speed. So graphene has a promising prospect in the field of microelectronics, such as the preparation of RRAM memory. At the same time, the surface of graphene oxide (GO) contains a lot of oxygen-containing functional groups, like carboxyl, hydroxyl group and epoxy group, and a large number of conjugate structure, so graphene oxide has certain fluorescence characteristics and can be applied to light emitting devices. Therefore, according to its excellent optical and electrical properities, this thesis mainly described fabracation of the graphene-based RRAM memory and graphene quantum dot-based fluorescent composite material, and explored the application in the related field.Conventional RRAM memory active layer materials mostly are perovskite oxide, binary transition metal oxides (e.g., NiO, TiO2, ZnO, etc.), sulfur compounds, organic semiconductor materials, and amorphous silicon. Compering with these materials, graphene oxide (GO) surface contains a large number of hydrophilic functional groups, which makes GO be well capable of dispersing in water, and forming large-area uniform film easily. And the band gap stage and electrical conductivity can be tuned by changing the content or types of oxygen-bearing functional groups. Thus, GO is expected to become the next generation active material of RRAM. Moreover, silver nanoparticles (AgNPs) could be attached at defects in GO plane, severed as an active center attracting electrons and a promoted agent for GO plane to develop its electronic properties. Herein, we successfully constructed an Al/AgNPs-GO/ITO structured RRAM, in which AgNPs-GO is active materials, Al severs as the top electrode and ITO glass is the bottom electrode. And characterized its electrical properties, and morphology for each part of it. Finally, we determined that it has good electrical bistability.Despite its excellent electrical properties, graphene and its derivatives also have terrific optical properties. Graphene quantum dots (GQDs) as a new fluorescent material with excellent biocompatibility, optical stability, tunable fluorescent properties, have deep potential of application in the photovoltaic device. But it is needed to form pattern on a substrate before GQDs integrating with other solid-state devices. In this thesis, GQDs with uniform plant size range from 1.50 nm to 4.00 nm were prepared, of which mean size is 2.21 nm.As-prepared GQDs had good photoluminescence (PL) properties and well dispersity. Moreover, we further designed GQDs/light-cured resin composite, which formed many different colorless and transparent patterns with PL properties by light-curing process, proving that the further applications in light emitting devices.In summary, this paper applied graphene-based composite material in the field of photoelectric information storage. We fabricated the Al/AgNPs-GO/ITO RRAM memory and provided more choices for active material of RRAM memory. At the same time, we prepared GQDs with good fluorescence properties. And as-prepared GDQs dispersed well in the photopolymerizable resin. Then we patterned GDQs/polymer nanocomposites through mask-based lithography, proving the further applications in light emitting devices.