氧化石墨烯與氧化石墨烯金屬奈米粒子複合物之雷射製程應用與探討

Characterizations of Graphene Oxides and Composites of Graphene Oxides and Metallic Nanoparicles Using Laser Ablation and Reduction

林威庭(Wei-Ting Lin)

指導教授 ： 何正榮

國立中正大學/工學院/機械工程學系/碩士(2012年)

摘要

本文主要探討氧化石墨烯(Graphene oxides, GOs）與氧化石墨烯/金屬奈米粒子複合材料（Composites of graphene oxides and metallic nanoparticles, GOs/MNPs）在雷射剝蝕還原（Laser ablation and reduction, LAR）作用後形成還原石墨烯（rGOs）與還原石墨烯/金屬奈米粒子複合物（rGOs/MNPs）電性表現與場發效應特性，並且探討相關機制與特性。

第一部分是銀奈米粒子與氧化石墨烯之複合材料（GOs/Ag-NPs）在雷射剝離還原作用後之電性表現，結果顯示複合薄膜（rGOs/Ag-NPs）之導電性與不含銀奈米粒子之氧化石墨烯薄膜（rGOs）相較並沒有明顯提升，推測原因可能是在LAR過程中因金屬奈米粒子之汽化剝離，使rGOs/Ag-NPs薄膜有破裂或不平整，致使rGOs/Ag-NPs薄膜之電性無法因金屬奈米粒子的添加而有效地提升。將銀奈米粒子置換成相對更穩定、導電度更佳的金奈米粒子，結果也相似。

第二部分則是探討在LAR過程中，因雷射作用使rGOs造成薄膜表面不平整所增強的場發效應（Field emission effect）。結果顯示使用LAR，可以使rGO產生明顯的場發效應，且其增強明因子顯地高於以加熱還原rGO薄膜的製備方法。

關鍵字

金屬奈米粒子 ； 雷射 ； 氧化石墨烯 ； 場發效應

並列摘要

The thesis aims to study the conductivity and the field-effect characteristics of the reduced graphene oxides (rGOs) and the composites of reduced graphene oxides and metallic nanoparticles (rGOs/MNPs), which are generated by the technique of laser ablation and reduction (LAR) and reduced respectively from graphene oxides (GOs) and the composite of graphene oxides and metallic nanoparticles (GOs/MNPs).
The first focus is to study the effect of MNPs on the conductivity of the rGOs/MNPs composite. Results show that even containing the silver nanoparticles (Ag-NPs) in the initial graphene oxides, the conductivity of the resulting rGOs/Ag-NPs films is not further improved when compared it with the rGOs films. Because the existence of MNPs might result in additional ruptures and splits on the film surfaces during the LAR process that further damaged and deteriorated the paths for carrier transport and degraded the film’s conductivity. The trend was still the same and neither the modification in film conductivity when the silver nanoparticles were replaced by the gold nanoparticles, which are more stable and with higher conductivity than silver nanoparticles.
The increase of surface protuberances, generated during the LAR process, are, however, very positive to the field emission of electrons. The second focus of this study is thus on this matter. Results showed that the enhancement factors of the field emission effect of the rGOs reduced by LAR were much higher than those rGOs obtained using thermal reduction.

並列關鍵字

Metal nanoparticles ； Laser ； Graphene Oxide ； Field emission

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