Fabrication of Graphene Quantum Dots by Chemical Synthesis Process and Analyses of Optical and Electrical Properties

Abstract

In this review study the emphasis has been given on the meticulous discussion of traditional and low cost methods as well as current development in preparation of modern quantum dots and the analyses of its optical and electrical properties Graphene Quantum Dots (GQDs) inherit some of the useful properties of bulk graphene which leads to its unique possession properties from bulk graphene due to the quantum confinement and edge effects As an emerging material GQDs presents a new open world for broad research area from synthesis explanation of properties to promising applications This thesis uses chemical synthesis process to produce the graphene quantum dots and then we transfer it to glass substrate After we prepare the specimen then we perform experiments We investigate the quality by Raman analysis We also investigate the particles height and roughness of specimens The optical properties such as transmittance and reflectance were analysed The last experiment to perform was Hall Effect analyser for electrical properties The results show that specimens with high synthesizing temperature of 150°C have highest Raman intensity and high mean diameter of 6 12 nm The advantage of high Raman intensity also helps in increasing the carrier mobility and concentration of the specimens The specimen with highest temperature and highest surface roughness of 10 20 nm also has highest transmittance and lowest reflectance percentage The optical properties are recognised to be size dependant and as the size of particle grows bigger the optical and electrical properties increase The specimens with increasing synthesizing temperature have increasing electrical properties because of free electrons that move to conduction band which increases the number of holes and electrons in the concentration

Date of Award	2019
Original language	English
Supervisor	Jen-Fin Lin (Supervisor)