Studies On Preparation And Properties Of Graphene-based Photodetectors

Since the announcement of Nobel Prize in Physics in 2010, graphene has attracted extensive interests in the research fields. In recent years, the government has enacted relevant policies to promote the development of graphene industry,thus studies on graphene related research has both theoretical and practical significance. In terms of the unique physical and chemical properties, graphene is widely used for electronics, optics, magnetic, biomedicine, catalysis, energy storage and sensor industry. The key technology for graphene related devices is to optimize its structure and properties. Therefore, this thesis focused on the application of graphene material in optoelectronic devices, combined graphene with different semiconductor material, optimized characteristics of heterojunction and photo-electricity response under ultraviolet?UV? light were investigated.This thesis reviews structures, common synthesis methods, physical properties and main application fields of graphene related 2D material; growth and characterization of Ga₂O₃ based semiconductor thin film; preparation and performance optimization of single/double-layer graphene photodetectors;graphene-like 2D material extended research.The main contributions in this thesis including: The graphene was grown by chemical vapor deposition on Cu substrate. Then, the single-layer graphene was separated by etching Cu substrates using FeCl3. The separated floating graphene sheet was transferred to the top surface of Ga₂O₃/SiC heterojunction. By replacing the top electrodes from Au/Ti to single-layer graphene, the device show more obvious rectifying characteristics and enhanced UV photoresponse. The Ilight/Idark under 254 nm illumination increases from 4.81 to 63.31 and the responsivity increases from 7.14×10-4 A/W to 0.18 A/W. Furthermore,graphene/SiC and graphene/GaAs heterojunctions, single/double-layer graphene solar cells have also been investigated.