本論文主要探討以化學氣相傳導法成長之硒化銦(InSe)層狀半導體奈米結構光電導及電傳輸特性。利用機械剝離法將硒化銦單晶分離成二維奈米結構，並利用聚焦式離子束顯微鏡製作二維奈米結構之歐姆電極。對硒化銦奈米薄片進行光電導量測，發現具有明顯的光電流反應，且隨著光強度增加，光電流也表現出非線性的增加。在相同的綠光雷射波長條件下，藉由比較不同層狀半導體材料之光電流，發現硒化銦奈米結構有著最佳的光響應。所記算出的歸依化光電導增益，硒化銦至少大於所有層狀半導體奈米結構兩個數量級。在不同雷射波長下，發現硒化銦奈米薄片對紫外光具有較佳的光電流反應。藉由環境變化之光電導量測，顯示硒化銦遵循著氧敏化光電導機制。造成硒化銦奈米薄片具有最佳的光電導特性之物理機制也將在本論文中探討。

Photoconduction and electronic transport properties in the direct-bandgap layer semiconductor of hexagonal indium selenide(InSe)grown by chemical vapor transport (CVT)have been investigated. The InSe layer nanostructure devices were fabricated using focused-ion beam (FIB) deposition and platinum (Pt) as the contact metal. By using different excitation wavelength, the InSe nanosheets show a higher photoresponse to the ultraviolet light illumination.The photocurrent increases nonlinearly with an increase at light intensity.Notably, under the same wavelength excitation , the InSe nanosheet photodetectors show the optimal responsivity and detectivity compared to most of the layer semiconductor nanostructures. The normalized gain, which defines the inherent photocurrent collection efficiency , of the In Senanosheets is over two orders of magnitude higher than those of the otherlayer materials. The environment-dependent photoconductivity measurement indicates that the InSe nanomaterials follow the oxygen-sensitive photoconduction mechanism. The physical origins resulting in the superior photoconductivity and detector performance in the InSe nanosheets were also discussed.

[1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, M. Y. Katsnelson, I. V. Grigorieva, S. V. Dubonos, A. A. Firsov, " Two-dimensional gas of massless Dirac fermions in graphene," vol. 438,doi:10.1038,(2005)
[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] S. Tongay, H. Sahin, C. Ko, A. Luce, W. Fan, K. Liu, J. Zhou, Y. S. Huang, C. H. Ho, J. Y. Yan, D. F. Ogletree, S. Aloni, J. Ji, S. S. Li, J. B. Li, F. M. Peeters, J. Q. Wu, “Monolayer behaviour in bulk ReS2 due to electronic and vibrational decoupling,” Nat. Commun., Vol. 5, pp. 3252 (2014).
[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] Wei Feng, Wei Zheng, Wenwu Cao, and PingAn Hu “Back Gated Multilayer InSe Transistors with Enhanced Carrier Mobilities via the Suppression of Carrier Scattering from a Dielectric Interface,” Adv. Mater, Vol. 26, pp. 6587(2014).
[8]Wei Feng, Xin Zhou, Wei Quan Tian, Wei Zheng and PingAn Hu, “Performance improvement of multilayer InSe transistors with optimized metal contacts,” Phys.Chem.Chem.Phys., Vol. 17, pp. 3653-3658 (2015).
[9]張冠英, “X光能譜分析儀”.
[10]B. D. Cullity, S. R. Stock, “Elements of X-ray diffraction,”Prentice Hall, New Jersey (2001).
[11]A. Beiser, “Concepts Of Modern Physics,”McGraw-Hill Education (India) Pvt Limited (2003).
[12]P. E. J. Flewitt and R. K. Wild, “Physical methods for materials characterization,” IOP Publishing, Bristol, (1994).
[13]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).
[14]A. A. Tseng, “Recent developments in micromilling using focused ion beam technology,”J. Micromech. Microeng., Vol. 14, pp. R15–R34, (2004).
[15]A. A. Tseng, “Recent Developments in Nanofabrication using Focused Ion Beams,”Small, Vol. 1, pp. 924–939, (2005).
[16]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)
[17]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).
[18]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).
[19]D. A. Chenet, O. B. Aslan, P. Y. Huang, C. Fan, A. M. van der Zande, T. F. Heinz, J. C. Hone, “In-Plane Anisotropy in Mono- and Few-Layer ReS2 Probed by Raman Spectroscopy and Scanning Transmission Electron Microscopy,” Nano Lett., Vol. 15, pp. 5667-5672 (2015).
[20]C. H. Ho, Y. S. Huang, K. K. Tiong, “In-plane anisotropy of the optical and electrical properties of ReS2 and ReSe2 layered crystals,” J. Alloy. Compd., Vol. 317, pp. 222-226 (2001).
[21]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).
[22]Y. Depeursinge, A. Baldereschi, Physica, 1981, 105B, 324-328.
[23]I. Mahboob, T. D. Veal, C. F. McConville, H. Lu, W. J. Schaff, “Intrinsic Electron Accumulation at Clean InN Surfaces,” Phys. Rev. Lett., Vol. 92, pp. 036804 (2004).
[24]P. Bhattacharya, “Semiconductor optoelectronic devices,” Prentice Hall, New Jersey, Vol. 8, pp. 346-351, (1997).
[25]M. Razeghi, A. Rogalski, “Semiconductor ultraviolet detectors,”J.Appl. Phys., Vol. 79, pp. 7433-7473, (1996).
[26]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).
[27]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).
[28]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).
[29]黃怡華,"二硫化鈮與二硒化鈮層狀逆米材料之電傳輸特性"
[30]N.M. GASANLY , B.M. YAVADOV , V.I. TAGIROV , E .A. VINOGRADOV, “Infrared and Raman Spectra of Layer InSe Single Crystals,” phys. stat. sol. (b) 89, K43 (1978)
[31]Sidong Lei, Liehui Ge, Sina Najmaei, Antony George, Rajesh Kappera, Jun Lou, Manish Chhowalla, Hisato Yamaguchi, Gautam Gupta, Robert Vajtai, Aditya D. Mohite, ,and Pulickel M. Ajayan, “Evolution of the Electronic Band Structure and Efficient Photo-Detection in Atomic Layers of InSe” ACS Nano, Vol 8, NO.2, 1263 – 1272, (2014)
[32]B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti and A. Kis, “Single-layer MoS2 transistors”, NATURE NANOTECHNOLOGY, VOL 6, ( 2011)
[33]O. Madelung , Semiconductors: Data Handbook, Springer, London2003 , Ch. 20 , p. 530
[34]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).
[35]沈韋竹,“二硫化鉬及二硫化鎢層狀半導體奈米結構之厚度相依電傳輸特性”
[36]陳家茂,“硫化鎵二維奈米結構之電傳輸特性”
[37]Y. H. Huang, R. S. Chen, J. R. Zhang and Y. S. Huang, “Electronic transport in NbSe2 two-dimensional nanostructures: semiconducting characteristics and photoconductivity”, Nanoscale, Vol.7, 18964–18970, (2015).