摻雜氮原子大面積二維石墨烯的製程與其光學及電學特性研究

Synthesis and investigation of optical and electrical features for large-scale two-dimensional nitrogen-doped graphene

盧郁芬(Yu-Fen Lu)

指導教授 ： 梁啟德

共同指導教授 ： 李連忠(Lain-Jong Li)

國立臺灣大學/理學院/物理研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01865

摘要

本篇論文主要在研究大面積摻雜氮原子之二維石墨烯，內容包含下列兩個主題：

1.摻雜氮原子大面積二維石墨烯的製程以及光學鑑定:

本論文第一個主題關於摻雜氮原子大面積二維石墨烯的製程。自從2004年，單層的graphene用膠帶取得之後，grpahene 已經成為目前最熱門研究的題目之一。但是由於膠帶撕黏得到的graphene面積太小，無法廣泛利用。而化學氣相沉積法(chemical vapor deposition)是目前常用來成長大面積graphene的方法之一。
摻入其他原子使其原本電子結構產生變化是一個在半導體產業常用的方法之一。氮含有五個價電子，相較於碳多了一個。多餘的電子會提高原本的費米能階，使graphene呈現n-type。s-triazine是一個含有三個氮原子且有六環結構的小分子。在本論文，我們把 s-triazine當作precursor，期望在高溫下，triazine裂解並且重新組合，形成nitrogen-doped graphene (NG)。我們採取低壓的CVD系統，以及用銅箔當作催化基板。固定參數，改變其生長溫度，做一系列樣品的鑑定，例如AFM、XPS、Raman 等等的分析。最後再轉印在矽基板以及砷化鎵上，以便後續的電性量測。

2.摻雜氮原子大面積二維石墨烯的載子傳輸機制:

本論文第二個主題研究關於不同成長溫度下NGs 其載子的傳輸機制。我們量測了不同成長溫度下樣品的R-T圖，發現不同成長溫度下製成的樣品，電性上有所不同。樣品對外界溫度的相依性也會隨著成長溫度的提高而減弱，且在700℃成長的樣品，觀察到其載子有variable-range hopping的行為；但隨著成長溫度增高，對外界溫度的相依性就減弱了許多，反而越像graphene的性質。
另外一個部分，我們將樣品進行post-annealing，取得R-T圖以及拉曼光譜的檢定， 與之前的樣品比較，做光學以及電性的鑑定與分析。

關鍵字

氮摻雜石墨烯 ； 化學氣相沉積法 ； 三嗪拉曼光譜 ； 原子力顯微鏡 ； X射線光電子能譜

並列摘要

This thesis focuses on the synthesis of large-scale two-dimensional nitrogen-doped graphene (NG) and investigation of optical and electrical features of NGs. It consists of the following two parts:

1.The synthesis of large-scale two-dimensional NGs:

The first part of the thesis is focused on the synthesis of large-scale two-dimensional nitrogen-doped graphene. Since the Manchester research group obtained graphene by adhesive tapes, graphene has attracted enormous attention. However, the exfoliated graphene is limited to small sizes. Large-scale graphene has been successfully obtained by chemical vapor deposition (CVD), which is adopted in this study.
In this study, the 1,3,5-triazine (also called s-triazine), which is a six-membered nitrogen heterocycles, was chosen as the precursor to produce the nitrogen-doped graphene on the copper foil, acting as the catalyst, in a low-pressure CVD system. The controlling parameter for the synthesis is the growth temperature. Characterizations for the NGs grown at various temperatures were carried out by Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy

2.Electrical properties of NGs

The second part of the thesis focuses on the transport behavior of carriers in NGs. The temperature dependences of resistance indicated that the transport behavior was strongly correlated to the doping concentration of nitrogen, which depended on the growth temperature. To complete the study of NGs, the optical and electrical characteristics of annealed NGs was also investigated. The results of resistance-temperature (R-T) relation for annealed NGs show that the electrical transport in annealed NGs exhibited similar to that of the pristine graphene, indicating NGs can be restored to some extent. Raman spectrum of the annealed NGs is also consistent with the results of the R-T measurements.

並列關鍵字

Nitrogen-doped graphene ； Chemical vapor deposition ； Triazine ； Raman spectroscopy ； Atomic force microscopy ； X-ray photoelectron spectroscopy

參考文獻

Chapter 1

[1] A. K. Geim and K. S. Novoselov, Nature Mater. 6, 183 (2007).

[2] Duhee Yoon and Hyeonsik Cheong, Raman Spectroscopy for Characterization of Graphene (Springer, 2012).

[4] Yuanbo Zhang, Yan-Wen Tan, Horst L. Stormer and Philip Kim, Nature 438, 201 (2005).

[9] T. B. Martins, R. H. Miwa, Antônio J. R. da Silva, and A. Fazzio, Phys. Rev. Lett. 98, 196803 (2007).