簡易檢索 / 詳目顯示

回結果列表
研究生： 黃世傑
Shih-Chieh Huang
論文名稱： 二硒化鎢p型層狀半導體之電傳輸特性
Electronic Transport Properties in WSe2 p-type Layer Semiconductors
指導教授： 趙良君
Liang -Chiun Chao
陳瑞山
Ruei-San Chen
口試委員: 趙良君
Liang -Chiun Chao
陳瑞山
Ruei-San Chen
李奎毅
Kuei-Yi Lee
邱雅萍
Ya-Ping Chiu
學位類別： 碩士
Master
系所名稱： 電資學院 - 光電工程研究所
Graduate Institute of Electro-Optical Engineering
論文出版年： 2017
畢業學年度： 105
語文別： 中文
論文頁數： 97
中文關鍵詞： 二硒化鎢 、層狀半導體 、p型 、電傳輸
外文關鍵詞： Tungsten Diselenide, Layer Semiconductors, p-type, Electronic Transport
相關次數： 點閱：238  下載：5 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  •  上一筆

    • 本論文主要探討以化學氣相傳導法(CVT)所成長的六方晶系(2H) 二硒化鎢(WSe2)層狀半導體之奈米結構電傳輸特性。使用熱探針與的場效應電晶體(FET)量測法，確認此二硒化鎢單晶為P型半導體。並利用機械剝離法將二硒化鎢單晶分離成二維奈米結構，再利用聚焦式離子束技術製作二維奈米結構之良好的歐姆接觸電極。二硒化鎢奈米結構的電導率大約為10~100 (S/cm) 上下，變溫暗電導量測可得到其載子活化能為5 meV，並且用FET量測法得到遷移率為14 cm2 V-1 s-1。電極製作前藉由將SiO2覆蓋在樣品表面，以避免離子束轟擊而導致樣品的本質特性改變。此外，以532nm波長的綠光雷射進行光電導量測，奈米結構與塊材均呈現出明顯的光電流特性，光電流隨著光強度增加而呈現線性增加。由計算光電導增益值發現，奈米結構高於塊材將近五個數量級。

    The electronic transport properties in two-hexagonal structure layer semiconductor of tungsten diselenide (WSe2) grown by chemical vapor transport (CVT) have been investigated. The hot-probe method and field-effect transistor (FET) measurement confirmed that the used WSe2 single crystal is a p-type semiconductor. The WSe2 layer nanostructure devices were fabricated using focused-ion beam (FIB) deposition and platinum (Pt) as the contact metal. The conductivity of WSe2 nanostructures prepared by mechanical exfoliation exhibit around 10 to 100 (S/cm). The activation energy of carrier was obtained to be 5 meV by the temperature-dependent conductivity measurement. The hole mobility defined by the FET measurement is approximately 14 cm2 V-1 s-1. A thin SiO2 film was coated on the surface of nanoflakes to prevent the potential surface damage by the ion beam bombardment during the FIB processing. In addition, photoconductive properties in the WSe2 nanostructures and bulks by the excitation of the wavelength of 532 nm were also investigated. The photocurrents of WSe2 nanostructures and bulks are linearly dependent on the light intensity. The WSe2 nanostructures exhibit high photoconductive gain which is five orders of magnitude higher than their bulk counterparts.

    中文摘要 ...... I Abstract ...... II 誌謝 ...... III 目錄 ...... IV 圖目錄 ...... VII 表目錄 ...... XI 第一章 緒論......1 第二章 實驗方法......3 2.1 二硒化鎢單晶製備方法......3 2.2 二硒化鎢之形貌與結構特性檢測......4 2.2.1 拉曼散射儀 (Raman scattering spectroscopy)......4 2.2.2 X光繞射儀 (X-ray diffractometry, XRD)......7 2.2.3 掃描式電子顯微鏡 (scanning electron microscopy, SEM)......10 2.2.4 雙束型聚焦離子束顯微鏡 (dual beam field emission focused ion beam, FIB)......12 2.2.5 原子力學顯微鏡 (atomic force microscopy, AFM)......16 2.2.6 熱探針法(hot probe method)......19 2.3 二硒化鎢奈米結構元件製作......21 2.3.1 元件基板製作......21 2.3.2機械式剝離法將層狀材料分散......22 2.3.3 層狀樣品電極製作......25 2.4 奈米薄片之暗電導特性研究......27 2.4.1 電流對電壓曲線量測(current-voltage measurement)......27 2.4.2 溫度變化之暗電導量測(temperature-dependent dark current measurement)......28 2.4.3 奈米材料場效應電晶體(field effect transistor)特性研究......28 2.5 奈米材料之光電導特性研究......28 第三章 結果與討論......32 3.1二硒化鎢層狀單晶與奈米材料之表面形貌與結構分析......32 3.1.1表面形貌......32 3.1.2晶體結構......35 3.2 二硒化鎢元件之SEM形貌分析......37 3.2.1二硒化鎢奈米結構元件製作......37 3.2.2二硒化鎢塊材元件製作......39 3.3利用原子力顯微鏡 (AFM) 定義層狀奈米元件厚度......41 3.4熱探針量測結果之分析......43 3.5 二硒化鎢奈米結構元件之電傳導厚度效應......45 3.5.1 二硒化鎢厚度相依之電導率......45 3.5.2 表面主導之電傳導特性......52 3.5.3 表面主導之電傳導特性......55 3.5.4低溫電導率分析......61 3.6 二硒化鎢功率相依光電導量測......66 3.6.1層狀半導體塊材及奈米結構環境變化功率相依光導量測......66 3.7二硒化鎢場效應電晶體(FET)量測分析......77 第四章 結論......79 參考文獻......81 圖目錄 圖2-1 拉曼光譜系統圖。......6 圖2-2 布拉格定律示意圖[14]。......9 圖2-3 D2 PHASER X光繞射儀器儀器圖。......9 圖2-4 掃描式電子顯微鏡。......11 圖2-5 掃描式電子顯微鏡示意圖[18]。......11 圖2-6 聚焦離子束系統。......14 圖2-7 聚焦離子束系統示意圖 [21]。......15 圖2-8 BRUKER-ICON2-SYS 原子力顯微鏡(AFM)圖。......18 圖2-9(A)熱探針法量測圖 (B)烙鐵於待測樣品正端加熱。......20 圖2-10 機械式剝離法示意圖。......24 圖2-11 震落法示意圖。......24 圖2-12 元件基板示意圖。......26 圖2-13層狀材料元件示意圖。......26 圖2-14 低溫四點探針量測系統。......29 圖2-15 KEITHLEY 4200-SCS 半導體參數量測儀。......29 圖2-16 KEITHLEY 2614B多功能電表。......30 圖2-17 搭配KEITHLEY 2614B多功能電表之低溫量測系統。......30 圖 2-18 光電導量測實驗架構圖。......31 圖3-1 層狀二硒化鎢塊材單晶圖。......33 圖3-2經機械剝離後於膠帶上之二硒化鎢微米尺度單晶SEM圖。......33 圖3-3 二硒化鎢原子排列示意圖[27]。......34 圖3-4 二硒化鎢塊材之拉曼譜線圖。......36 圖3-5二硒化鎢單晶塊材之XRD譜線圖。......36 圖3-6 經機械剝離法後樣品灑落在預電極基板上之SEM圖。......38 圖3-7 利用FIB製作完成之(A)兩電極及(B)四電極元件SEM圖。......38 圖3-8 螺旋測量儀估算二硒化鎢單晶厚度之影像。......40 圖3-9 銀膠製作二硒化鎢塊材元件。......40 圖3-10二硒化鎢奈米結構之AFM量測圖及高度剖視圖。......42 圖3-11 熱探針法(A)初始電壓值 (B)加熱後之電壓值。 44 圖3-12 二硒化鎢奈米結構之兩接點與四接點式電極電導率比較圖和不同厚度電導率比較圖。......48 圖3-13 二硒化鎢奈米結構之電導對應厚度分布圖(對數作圖)。......50 圖3-14 二硒化鎢奈米結構之電導率對應厚度分布圖(對數作圖)。......50 圖3-15 二硒化鎢奈米結構與塊材之電導率對應厚度分布圖(對數作圖)。......51 圖3-16 材料電導率對厚度取對數示意圖。......51 圖3-17 表面電導與塊材電導之等效電路示意圖。......54 圖3-18 奈米元件上表面剖面示意圖。......57 圖3-19 在基板上鍍SIO2絕緣材料的二硒化鎢SEM 圖。......58 圖3-20鍍上SIO2絕緣材料後製作的元件SEM 圖。......59 圖3-21 加入具有SIO2保護層製作的二硒化鎢奈米結構電導率數據後之電導率分佈圖。......60 圖3-22 半導體能隙之活化能示意圖。......63 圖3-23 二硒化鎢奈米結構升溫過程電導率對溫度的變化圖。......64 圖3-24 二硒化鎢塊材升溫過程電導率對溫度的變化圖。......64 圖3-25 二硒化鎢奈米結構升溫過程電導率對溫度的ARRHENIUS作圖。......65 圖3-26 二硒化鎢塊材升溫過程電導率對溫度的ARRHENIUS作圖。......65 圖3-27 二硒化鎢奈米結構不同環境之功率相依光響應圖。......71 圖3-28 二硒化鎢奈米結構不同環境之功率相依光電流圖。......71 圖3-29 二硒化鎢奈米結構反應率之功率相依圖。......72 圖3-30 二硒化鎢奈米結構不同環境之增益功率相依圖。......72 圖3-31 二硒化鎢奈米結構不同環境之歸一化增益功率相依圖。......73 圖3-32 二硒化鎢奈米結構之載子活期功率相依圖。......73 圖3-33 二硒化鎢塊材不同環境之功率相依光響應圖。......74 圖3-34 二硒化鎢塊材不同環境之功率相依光電流圖。......74 圖3-35 二硒化鎢塊材反應率之功率相依圖。......75 圖3-36 二硒化鎢塊材不同環境之增益功率相依圖。......75 圖3-37 二硒化鎢塊材不同環境之歸一化增益功率相依圖。......76 圖3-38 二硒化鎢奈米結構FET示意圖。......78 圖3-39 二硒化鎢奈米結構FET之IV曲線。......78 表目錄 表3-1多層二硒化鎢奈米元件厚度與電導率統計表。......49

    [1]K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, A. A. Firsov, “Electric Field Effect in Atomically Thin Carbon Films,” Science, Vol. 306, pp.666-669 (2004).
    [2]K. S. Novoselov, D. Jiang, F. Schedin, T. J. Booth, V. V. Khotkevich, S. V. Morozov, et al., “Two-dimensional atomic crystals,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 102, pp. 10451-10453 (2005).
    [3]A. Splendiani, L. Sun, Y. Zhang, T. Li, J. Kim, C. Y. Chim, G. Galli, and F. Wang, “Emerging Photoluminescence in Monolayer MoS2,” Nano Lett., Vol. 10, pp. 1271-1275 (2010).
    [4]K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, “Atomically Thin MoS2: A New Direct-Gap Semiconductor,” Phys. Rev. Lett, Vol. 105, pp. 136805 (2010).
    [5]P. Tonndorf, R. Schmidt, P. Böttger, X. Zhang, J. Börner, A. Liebig, M. Albrecht, C. Kloc, O. Gordan, D. R. T. Zahn, S. Michaelis de Vasconcellos, R. Bratschitsch, “Photoluminescence emission and Raman response of monolayer MoS2, MoSe2, and WSe2,” OPTICS EXPRESS, Vol. 21, No. 4(2013)
    [6]R. S. Chen, C. C. Tang, W. C. Shen and Y. S. Huang, “Thickness dependent electrical conductivities and ohmic contacts in transition metal dichalcogenides multilayers,” Nanotechnology, Vol. 25, pp. 415706 (2014).
    [7]J. S. Ross, P. Rivera, J. Schaibley, L. W. Eric, H. Yu, T. Taniguchi, K. Watanabe, J. Yan, D. Mandrus, D. Cobden, W. Yao, “Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction,” Nano Lett, Vol. 17, pp. 638-643 (2017).
    [8]H. Bhunia, A. Bera, A. J. Pal, “Current Rectification through Vertical Heterojunctions between Two Single-Layer Dichalcogenides (WSe2|MoS2 pn-junctions),” ACS Appl. Mater, Vol. 9, pp.8248-8254 (2017)
    [9]W. Zhang, M. H. Chiu, C. H.Chen, W. Chen, L. J. Li, A. T. S. Wee, “Role of Metal Contacts in High-Performance Phototransistors Based on WSe2 Monolayers,” ACS Nano, Vol. 8, pp. 8653-8661 (2014).
    [10]B. Lei, Z. Hu, D. Xiang, J. Wang, G. Eda, C. Han, W. Chen“Significantly enhanced optoelectronic performance of tungsten diselenide phototransistor via surface functionalization,” Nano Research, Vol. 10,pp. 1282-1291(2017).
    [11]H. Sun, H. Yang, L. Fang, J. Zhang, Z. Wang, T Jiang, “ Electro-photo modulation of the fermi level in WSe2/graphene van der Waals heterojunction,” Physica, Vol. 88, pp. 279–283(2017).
    [12]C. Hu, D. Dong, X. Yang, K. Qiao, D. Yang, H. Deng, S. Yuan, J. Khan, Y. Lan, H. Song, J. Tang, “ Synergistic Effect of Hybrid PbS Quantum Dots/2D-WSe2 Toward High Performance and Broadband Phototransistors,” Adv. Funct. Mater, Vol. 27, (2017).
    [13]C. Zhou, Y. Zhao, S. Raju, Y. Wang , Z. Lin, M. Chan, Yang Chai, “Carrier Type Control of WSe 2 Field-Effect Transistorsby Thickness Modulation and MoO 3 Layer Doping,” Adv. Funct. Mater, Vol. 26, pp. 4223-4230(2016).
    [14]S. G. Yi, S. H. Kim, S. Park, D. Oh, H. Y. Choi, N. Lee, Y. J. Choi, K. H. Yoo, “Mo1−xWxSe2‑Based Schottky Junction Photovoltaic Cells,” ACS Appl. Mater. Interfaces, Vol. 8, pp. 33811-33820(2016).
    [15]S. Hussain, S. A. Patil, D. Vikraman, A. A. Arbab, S. H. Jeong, H. S. Kim, J. Jung, “Growth of a WSe2/W counter electrode by sputtering and selenization annealing for high-efficiency dye-sensitized solar cells,” Applied Surface Science, Vol. 406, pp. 84-90, (2017).
    [16]張冠英, “X光能譜分析儀”.
    [17]B. D. Cullity, S. R. Stock, “Elements of X-ray diffraction,” Prentice Hall, New Jersey (2001).
    [18]P. E. J. Flewitt and R. K. Wild, “Physical methods for materials characterization,” IOP Publishing, Bristol, (1994).
    [19]A. A. Tseng, K. Chen, C. D. Chen, and K. J. Ma, “Electron Beam Lithography in Nanoscale Fabrication: Recent Development,” IEEE Trans. Electron. Packag. Manuf., Vol. 26, pp. 141–149, (2003).
    [20]A. A. Tseng, “Recent developments in micromilling using focused ion beam technology,” J. Micromech. Microeng., Vol. 14, pp. R15–R34, (2004).
    [21]A. A. Tseng, “Recent Developments in Nanofabrication using Focused Ion Beams,” Small, Vol. 1, pp. 924–939, (2005).
    [22]F. Braet, R. De Zanger, and E. Wisse, “Drying cells for SEM, AFM and TEM by hexamethyldisilazane: a study on hepatic endothelial cells,” Journal of Microscopy, Vol. 186, pp. 84–87, (1997)
    [23]Schleiermacher, A., “On the thermal conduction of gas,” Wiedeman. Ann. Phys, Vol. 34, pp, 623-646 (1888).
    [24]Golan, A. A. a. G, “Hot-probe method for evaluation of majority carries concentration in semiconductor thin films thin,” Electronics and Energetics, Vol. 26, pp. 187-195 (2013).
    [25]Y. M. Chang, H. Kim, J. H. Lee, and Y. W. Song, “Multilayered graphene efficiently formed by mechanical exfoliation for nonlinear saturable absorbers in fiber mode-locked lasers,” Appl. Phys. Lett., Vol. 91970, pp.211102 (2010).
    [26]C. Y. Nam, D. Tham, J. E. Fischer, “Disorder effects in focused-ionbeam-deposited Pt contacts on GaN nanowires,” Nano Lett., Vol. 5, pp. 2029-2033 (2005).
    [27]http://www.tu-chemnitz.de/physik/OFGF/research/alloys.php
    [28]C. Y. Nam, D. Tham, and J. E. Fischer, “Disorder effects in focused-ion-beam-deposited Pt contacts on GaN nanowires,” Nano Lett., Vol. 5, pp. 2029–2033 (2005).
    [29]林敬軒, “二硫化錸二維奈米結構之電傳輸特性“.
    [30]R. S. Chen, T. H. Yang, H. Y. Chen, L. C. Chen, K. H. Chen, Y. J. Yang, C. H. Su, C.R. Lin, “Photoconduction mechanism of oxygen sensitization in InN nanowires,” Nanotechnology, Vol. 22, pp. 5 (2011).
    [31]P. Bhattacharya, “Semiconductor optoelectronic devices,” Prentice Hall, New Jersey, Vol. 8, pp. 346-351, (1997).
    [32]M. Razeghi, A. Rogalski, “Semiconductor ultraviolet detectors,” J.Appl. Phys., Vol. 79, pp. 7433-7473, (1996).
    [33]R. S. Chen, H. Y. Chen, C. Y. Lu, K. H. Chen, C. P. Chen, L. C. Chen, Y. J. Yang, “Ultahigh photocurrent gain in m-axial GaN nanowires,” Appl. Phys. Lett., Vol. 91, pp. 223106 (2007).
    [34]S. Kumar, U. Schwingenschlogl, “Thermoelectric Response of Bulk and Monolayer MoSe2 and WSe2,” Chem. Mater. Vol. 27, pp. 1278-1284(2015).
    [35]R. S. Chen, W. C. Wang, C. H. Chan, H. P. Hsu, L. C. Tien, Y. J. Chen, “Photoconductivities in monocrystalline layered V2O5 nanowires grown by physical vapor deposition,” Nanoscale Res. Lett., Vol. 8, pp. 443 (2013).
    [36]J. D. Prades, R. Jimenez-Diaz, F. Hernandez-Ramirez, L. Fernandez-Romero, T. Andreu, A. Cirera, A. Romano-Rodriguez, A. Cornet, J. R. Morante, S. Barth, S. Mathur, “Toward a systematic understanding of hotodetectors based on individual metal oxide nanowires,” J. Phys. Chem. C, Vol. 112, pp. 14639-14644, (2008).
    [37]C. Fabrega, F. Hernandez-Ramirez, J. D. Prades, R. Jimenez-Diaz, T. Andreu, J. R. Morante, “On the photoconduction properties of low 93 resistivity TiO2 nanotubes,” Nanotechnology, Vol. 21, pp. 445703 (2010).
    [38]A. Beiser, “Concepts Of Modern Physics,” McGraw-Hill Education (India) Pvt Limited (2003).
    [39]H. Sahin, S. Tongay, S. Horzum, W. Fan, J. Zhou, J. Li, J. Wu, F. M. Peeters, “Anomalous Raman spectra and thickness-dependent electronic properties of WSe2,” PHYSICAL REVIEW, Vol 87, pp. 165409 (2013).
    [40]M. P. Deshpande, M. N. Parmar, N. N. Pandya, S. Chaki, S. V. Bhatt, “Studies on transport properties of copper doped tungsten diselenide single crystals,” Physica B, Vol 407, pp. 808-812 (2012).

    QR CODE