臺灣博碩士論文加值系統

本實驗主要使用拉曼光學顯微鏡(raman spectroscopy)，對鋪放在圖案化基板之二維材料-過渡金屬二硫化物進行光學及結構特性研究。研究樣品為二碲化鉬(MoTe2)，以及二硒化鎢(WSe2)。 我們以拉曼光學顯微鏡進行樣品的映像掃描(mapping)，得到拉曼訊號強度分佈圖，發現圖案化基板確實影響拉曼訊強度分佈的形式。且針對特定的波峰進行分析，得到相同區域的拉曼偏移的分佈，此結果與拉曼訊號強度分佈有明顯的相對應。在WSe2的PL(photoluminescence)光譜中，明確得到exiton因圖案化基板的差異，影響其波峰偏移的情形。由此證實二維材料可以通過圖案化基板改變層與層間的凡德瓦力（van der Waals），進而影響能隙的偏移與拉曼訊號的強度。
在實驗中，我們利用拉曼光學顯微鏡發現到過渡金屬二硫化物拉曼強度的映射圖形與其所受應力的區域，具有相關性的研究結果。

In this experiment, Raman spectroscopy was used to study the optical properties of two-dimensional material-transition metal dichalcogenides on patterned substrates. The materials used in our experiments include molybdenum dichloride (MoTe2) and tungsten diselenide (WSe2). We used a Raman optical microscope to perform 2D mapping of the sample to obtain a Raman signal intensity distribution map, and found that the patterned substrate did affect the Raman signal intensity distribution. Detail analysis of some of the Raman peaks shows that the distribution of the Raman shift strongly correlates to the Raman signal intensity distribution map in the same region. In the PL (photoluminescence) spectrum of WSe2, it is clear that the exciton peaks are affected by the patterned substrate. The strain in the two-dimensional material can be modulated via patterned substrate, thereby affecting the shift of the energy gap and the intensity of the Raman signal.

摘要 ................................ ................................ ................................ ................................ . i
Abstract ................................ ................................ ................................ .......................... ii
致謝 ................................ ................................ ................................ ............................... iii
目錄 ................................ ................................ ................................ ............................... iv
第一章 前言................................ ................................ ................................ .................. 1
第二章 實驗原理 ................................ ................................ ................................ .......... 3
2-1 MoTe 2與 WSe 2介紹 ................................ ................................ ........................... 3
2-2 Raman and PL ................................ ................................ ................................ 4
第三章 元件製作與量測 ................................ ................................ .............................. 6
3-1 基板的定位 ................................ ................................ ................................ .... 6
3-2 FIB pattern 製作................................ ................................ ........................ 8
3-3 元件製備 ................................ ................................ ................................ ...... 10
3-4 量測儀器 ................................ ................................ ................................ ...... 15
第四章 結果與討論 ................................ ................................ ................................ .... 18
4-1 實驗樣品介紹 ................................ ................................ .............................. 18
4-2 樣品 A MoTe2 on silicon-oxide plateau................................ ............... 20
4-3 樣品 B MoTe2 on silicon-oxide dot array................................ ........... 26
Correlation 相關係數 ................................ ................................ ................. 30
4-4 樣品C WSe2 on h-BN dot array................................ ............................... 35
第五章 結論 ................................ ................................ ................................ ................ 44
第六章 參考資料 ................................ ................................ ................................ ........ 46
附錄 ................................ ................................ ................................ .............................. 49

[1]. A. K. Geim, K. S. Novoselov, The rise of graphene. Nat. Mater.6, 183–191 (2007).

[2]. Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti, V.; Kis, A.Single-layer MoS2transisters.Nat. Nanotech 6, 147−150 (2011)

[3]. Dhakal, K. P.; Duong, D. D.; Lee, J.; Nam, H.; Kim, M. S.; Kan,M.; Lee, Y. H.; Kim, J. Confocal absorption spectral imaging of MoS2:Optical transition depending on the atomic thickness of intrinsic andchemically doped MoS2.Nanoscale 6, 13028−13035 (2014)

[4]. Shi, H.; Pan, H.; Zhang, Y.-W.; Yakobson, B. I. Quasiparticleband structures and optical properties of strained monolayer MoS2 and WS2. Phys. Rev. B: Condense Matter 87, 155304. (2013)

[5]. Song, J. C. W. & Gabor, N. M. Electron quantum metamaterials in van derWaals heterostructures. Nat. Nanotechnol.13, 986–993 (2018).

[6]. Island, J. O.; Kuc, A.; Diependaal, E. H.; Bratschitsch, R.; vander Zant, H. S. J.; Heine, T.; Castellanos-Gomez, A. Precise and reversible band gap tuning in single-layer MoSe2by uniaxial strain. Nanoscale 8,2589−2593. (2016)

[7]. Castellanos-Gomez, A.; Roldan, R.; Cappelluti, E.; Buscema, M.;Guinea, F.; van der Zant, H. S. J.; Steele, G. A. Local strain engineering in atomically thin MoS2.Nano Lett 13, 5361−5366. (2013)

[8]. Yang, S.; Wang, C.; Sahin, H.; Chen, H.; Li, Y.; Li, S. S.; Suslu,A.; Peeters, F. M.; Liu, Q.; Li, J.; Tongay, S. Tuning the Optical, Magnetic, and Electrical Properties of ReSe2 by Nanoscale Strain Engineering. Nano Lett 15, 1660−1666. (2015)

 
[9] Lloyd, D.; Liu, X.; Christopher, J. W.; Cantley, L.; Wadehra, A.;Kim, B. L.; Goldberg, B. B.; Swan, A. K.; Bunch, J. S. Band Gap Engineering with Ultra large Biaxial Strains in Suspended Monolayer MoS2.Nano Lett. 16, 5836−5841. (2016)

[10]. Desai, S. B.; Seol, G.; Kang, J. S.; Fang, H.; Battaglia, C.;Kapadia, R.; Ager, J. W.; Guo, J.; Ali, J. Strain-induced indirect to direct bandgap transition in multilayer WSe2.Nano Lett. 14, 4592−4597. (2014)

[11]. He,K.;Poole,C.;Mak,K.F.;Shan,J. Experimental demonstration of continuous electronic structure tuning via strain in atomically thin MoS2. Nano Lett. 13, 2931−2936. (2013)

[12]. S. Cho, S. Kim, J. H. Kim, J. Zhao, J. Seok, D. H. Keum, J. Baik, D.-H. Choe, K. J. Chang,K. Suenaga, S. W. Kim, Y. H. Lee, H. Yang, Phase patterning for ohmic homojunctioncontact in MoTe2. Science349, 625–628 (2015).
.
[13]. Liu, R.Y.; Ogawa, Y.; Chen, P.; Ozawa, K.; Suzuki, T.; Okada, M.; Someya, T.; Ishida, Y.; Okazaki, K.; Shin,S.; et al. Femtosecond to picosecond transient effects in WSe 2 observed by pump–probe angle-resolved photoemission spectroscopy. Sci. Rep. 7, 15981 (2017)

[14]. V. E. Fedorov, I. V. Mirzaeva, S. G. Kozlova, E. D. Grayfer, and M. V. Medvedev, in MIPRO, Proceedings of the 35th International Convention, Novosibirsk, Russia, 21–25 May (2012)

[15]. V. Podzorov , M. E. Gershenson , C. Kloc , R. Zeis , E. Bucher ,
Appl.Phys. Lett. 84 , 3301.(2004)

[16]. Dieter K. Schroder - Semiconductor material and device characterization. Chapter 10.9

[17]. Lezama, I. G.; Arora, A.; Ubaldini, A.; Barreteau, C.; Giannini, E.; Potemski, M.; Morpurgo, A. F. Indirect-to-direct band gap crossover in few-layer MoTe2. Nano Lett. 15, (4), 2336-2342 (2015)

 
[18]. Grzeszczyk, M.; Golasa, K.; Zinkiewicz, M.; Nogajewski, K.; Molas, M.R.; Potemski, M.; Wysmolek, A.;Babinski, A. Raman scattering of few-layers MoTe2. 2D Mater. 3, 025010 (2016)

[19]. Renpei.Liu - Simple Correlations and Simple Linear Regression

[20]. P. Tonndorf, R. Schmidt, P. Böttger, X. Zhang, J. Börner, A. Liebig, M. Albrecht, C. Kloc, O. Gordan, D. Zahn, S. Michaelis de Vasconcellos, and R. Bratschitsch, "Photoluminescence emission and Raman response of monolayer MoS2, MoSe2, and WSe2, Opt. Express 21, 4908-4916 (2013).

[21]. Froehlicher, G.; Lorchat, E.; Fernique, F.; Joshi, C.; Molina-Sanchez, A.; Wirtz, L.; Berciaud, S. Unified Description of the OpticalPhonon Modes in N-Layer MoTe2.Nano Lett. 15, 6481−9 (2015)

[22]. Aslan, O., Datye, I., Mleczko, M., Sze Cheung, K., Krylyuk, S., Bruma, A., Kalish, I., Davydov, A., Pop, E. and Heinz, T. Probing the Optical Properties and Strain-Tuning of Ultrathin Mo1–xWxTe2. Nano Letters, 18(4), pp.2485-2491. (2018)


[23]. Shenyang Huang, Guowei Zhang, Fengren Fan, Chaoyu Song, Fanjie Wang, Qiaoxia Xing, Chong Wang, Hua Wu & Hugen Yan. Nature Communications volume 10, 2447 (2019)