Synthesis and Optical Properties of Graphene Oxide Quantum Dots

• Main Authors: Kao-ChiWei, 高啟瑋
• Other Authors: Shen-Ji Lin
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/9tbj2t

碩士 === 中原大學 === 奈米科技碩士學位學程 === 104 === In this study, graphene oxide quantum dots (GOQDs) was produced using microwave with hydrothermal treatment route and pulsed laser ablation (PLA) method. The first study includes synthesis via microwave followed by hydrothermal route, PL enhancement, and characterization of structural, compositional and optical properties of GOQDs. The second study includes synthesis via PLA method, and characterization of the optical properties of GOQDs. A yellow-green photoluminescence GOQDs was produced under microwave with hydrothermal treatment. The initial yellow-green photoluminescence GOQDs was produced via microwave treatment of graphene oxide and NaOH solution. The photoluminescence (PL) of the yellow-green photoluminescence GOQDs initially produced was enhanced by further hydrothermal treatment. The structural, compositional and optical properties of the yellow-green photoluminescence GOQDs were measured and analyzed using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron (XPS) spectroscopy, ultra-violet visible (UV-Vis) absorption spectroscopy, and Photoluminescence (PL) spectroscopy. An excitation-dependent behavior in the yellow-green photoluminescence GOQDs was observed. We suggest that oxygen-related functional groups are responsible for the PL behavior of the yellow-green photoluminescence GOQDs. On the other hand, a blue photoluminescence GOQDs was produced via PLA method. The PL spectroscopy and time-resolved photoluminescence (TRPL) spectroscopy were used to study the steady state PL, carrier lifetime and temperature-dependent PL behavior of the blue photoluminescence GOQDs. A model based on self-trapped polaron excitons was proposed to explain the PL mechanism of the blue photoluminescence GOQDs.