由於溫室效應的影響，近來在能源消耗及溫室氣體排放的問題逐年增長，為了解決暖化與能源短缺問題，可在不消耗其他能源的前提下使建築自我減少或隔絕太陽光輻射溫度的吸收，將可有效改善室內冷卻的問題，達到節省能源、費用及改善空氣品質等目的。
具熱致變色性質之二氧化釩(VO2)會在接近於"68 °C" 的相變化溫度("T" _"t" )經歷一個完全可逆的半導體-金屬相變化，變伴隨著電性及光學性質的急遽變化，使其可應用在光/電切換裝置，如憶阻器、Mott場效應晶體管、可調式超材料、表面等離激元、抗反射裝置、智慧窗…等。然而純相VO2的"T" _"t" 還是太高，並不足以應用在與室溫溫度相關的應用端上，因此將改變薄膜厚度以及摻雜鎢離子來改變薄膜結構，使其具有低"T" _"t" 。
以往高品質摻鎢之VO2薄膜大多採用APCVD、AACVD、PLD及濺鍍法等方式製備，而在本篇研究中將使用至今尚未有文獻成功報導的電子束蒸鍍法作為薄膜製備之製程，並針對其晶體結構、化學成分及光學性質進行探討。
實驗結果顯示，VO2薄膜晶體結構會隨著退火溫度的提升，自VO2(B)轉換為VO2(M)結構。摻雜W離子之VO2薄膜(WxV1-xO2)，其部分釩離子的價態從V4+還原為V3+，而W離子以W6+的形式存在與VO2晶格中，造成VO2晶體結構的變化。在光學性質方面，VO2薄膜在"68 °C" 附近展現出優異的紅外光切換效率(〖"∆T" 〗_"IR" )，且"T" _"t" 隨著薄膜厚度的減少而些微降低；WxV1-xO2薄膜的"T" _"t" 則隨著W摻雜量增加而大幅度地降低，且伴隨著紅外光遮蔽能力的降低。此外，當W含量過多時甚至在室溫附近的溫度範圍內無法觀測到明顯的熱滯迴圈。

Thermochromic vanadium dioxide (VO2) undergoes a fully reversible semiconductor-metal transition (SMT) at a critical temperature (Tt) of ~68 °C with a dramatic change in electric and optical properties, which makes it an attractive candidate for its application in smart windows. Switchable VO2 and W-doped vanadium dioxide (WxV1-xO2) thin films are grown over quartz substrates via electron beam evaporation technique by using VO2 / WxV1-xO2 as targets at room temperature (RT) followed by post annealing process at different temperatures. The as-deposited films are amorphous, and that transform to monoclinic VO2 (VO2(M)) with (011)-preferred orientation after annealing at 500 °C under vacuum. The (011) peak of W-doped VO2 films shifts to a lower diffraction angle as compared with un-doped VO2 films which confirms the incorporation of W ions into the VO2 lattice. Temperature dependent optical transmittance measurement demonstrates the thermochromic properties, with a reduction in the phase transition temperature (Tt) as observed in W-doped VO2 films, which is attributed to the variation of electron structure in VO2 due to doping. The films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and optical transmittance measurement.

[1] A. Gonçalves, J. Resende, A. C. Marques, J. V. Pinto, D. Nunes, A. Marie, et al., "Smart optically active VO2 nanostructured layers applied in roof-type ceramic tiles for energy efficiency," Solar Energy Materials and Solar Cells, vol. 150, pp. 1-9, 2016.
[2] C. G. Granqvist, "Window coatings for the future," Thin Solid Films, vol. 193, pp. 730-741, 1990.
[3] S. Wang, M. Liu, L. Kong, Y. Long, X. Jiang, and A. Yu, "Recent progress in VO2 smart coatings: Strategies to improve the thermochromic properties," Progress in Materials Science, vol. 81, pp. 1-54, 2016.
[4] J. H. Gibson, "UVB Radiation: Definition and Characteristics," Colorado State University2003.
[5] Fondriest Environmental, Inc. “Solar Radiation & Photosynthetically Active Radiation.” Fundamentals of Environmental Measurements. 2014. Web. Retrieved from http://www.fondriest.com/environmental-measurements/parameters/weather/photosynthetically-active-radiation/
[6] G. Team, "GISS Surface Temperature Analysis (GISTEMP)," N. G. I. f. S. Studies, Ed., ed, 2017.
[7] S. Van Den Bergh, R. Hart, B. P. Jelle, and A. Gustavsen, "Window spacers and edge seals in insulating glass units: A state-of-the-art review and future perspectives," Energy and Buildings, vol. 58, pp. 263-280, 2013.
[8] J.-M. Dussault, L. Gosselin, and T. Galstian, "Integration of smart windows into building design for reduction of yearly overall energy consumption and peak loads," Solar Energy, vol. 86, pp. 3405-3416, 2012.
[9] E. Ando and M. Miyazaki, "Moisture degradation mechanism of silver-based low-emissivity coatings," Thin Solid Films, vol. 351, pp. 308-312, 1999.
[10] E. Ando and M. Miyazaki, "Moisture resistance of the low-emissivity coatings with a layer structure of Al-doped ZnO/Ag/Al-doped ZnO," Thin Solid Films, vol. 392, pp. 289-293, 2001.
[11] A. M. Al-Shukri, "Thin film coated energy-efficient glass windows for warm climates," Desalination, vol. 209, pp. 290-297, 2007.
[12] U. O. Krašovec, B. Orel, A. Georg, and V. Wittwer, "The gasochromic properties of sol–gel WO3 films with sputtered Pt catalyst," Solar Energy, vol. 68, pp. 541-551, 2000.
[13] G. Micocci, A. Serra, A. Tepore, S. Capone, R. Rella, and P. Siciliano, "Properties of vanadium oxide thin films for ethanol sensor," Journal of Vacuum Science & Technology A, vol. 15, pp. 34-38, 1997.
[14] C. G. Granqvist, "Electrochromics for smart windows: Oxide-based thin films and devices," Thin Solid Films, vol. 564, pp. 1-38, 2014.
[15] C. M. Lampert, "Electrochromic materials and devices for energy efficient windows," Solar Energy Materials, vol. 11, pp. 1-27, 1984.
[16] R. J. Colton, A. M. Guzman, and J. W. Rabalais, "Photochromism and electrochromism in amorphous transition metal oxide films," Accounts of Chemical Research, vol. 11, pp. 170-176, 1978.
[17] S. Nishio and M. Kakihana, "Evidence for Visible Light Photochromism of V2O5," Chemistry of Materials, vol. 14, pp. 3730-3733, 2002.
[18] G. V. Jorgenson and J. C. Lee, "Doped vanadium oxide for optical switching films," Solar Energy Materials, vol. 14, pp. 205-214, 1986.
[19] F. J. Morin, "Oxides which show a metal-to-insulator transition at the neel temperature," Physical Review Letters, vol. 3, pp. 34-36, 1959.
[20] F. Théobald, "Étude hydrothermale du système VO2-VO2,5-H2O," Journal of the Less Common Metals, vol. 53, pp. 55-71, 1977.
[21] F. Théobald, R. Cabala, and J. Bernard, "Essai sur la structure de VO2(B)," Journal of Solid State Chemistry, vol. 17, pp. 431-438, 1976.
[22] D. Hagrman, J. Zubieta, C. J. Warren, L. M. Meyer, M. M. J. Treacy, and R. C. Haushalter, "A New Polymorph of VO2Prepared by Soft Chemical Methods," Journal of Solid State Chemistry, vol. 138, pp. 178-182, 1998.
[23] C. Wu, F. Feng, J. Feng, J. Dai, J. Yang, and Y. Xie, "Ultrafast Solid-State Transformation Pathway from New-Phased Goethite VOOH to Paramontroseite VO2 to Rutile VO2(R)," Journal of Physical Chemistry C, vol. 115, pp. 791-799, 2011.
[24] A. Simo, B. Mwakikunga, B. T. Sone, B. Julies, R. Madjoe, and M. Maaza, "VO2 nanostructures based chemiresistors for low power energy consumption hydrogen sensing," International Journal of Hydrogen Energy, vol. 39, pp. 8147-8157, 2014.
[25] J. P. Pouget, H. Launois, T. M. Rice, P. Dernier, A. Gossard, G. Villeneuve, et al., "Dimerization of a linear Heisenberg chain in the insulating phases of V1-xCrxO2," Physical Review B, vol. 10, pp. 1801-1815, 1974.
[26] Y. Oka, T. Yao, N. Yamamoto, Y. Ueda, and A. Hayashi, "Phase Transition and V4+-V4+ Pairing in VO2(B)," Journal of Solid State Chemistry, vol. 105, pp. 271-278, 1993.
[27] N. Bahlawane and D. Lenoble, "Vanadium Oxide Compounds : Structure, Properties, and Growth from the Gas Phase," Chemical Vapor Deposition, vol. 20, pp. 299-311, 2014.
[28] J. M. Atkin, S. Berweger, E. K. Chavez, M. B. Raschke, J. Cao, W. Fan, et al., "Strain and temperature dependence of the insulating phases of VO2 near the metal-insulator transition," Physical Review B, vol. 85, p. 020101, 2012.
[29] T. J. Huffman, C. Hendriks, E. J. Walter, J. Yoon, H. Ju, R. Smith, et al., "Insulating phases of vanadium dioxide are Mott-Hubbard insulators," Physical Review B, vol. 95, p. 075125, 2017.
[30] D. Johansson, "VO2 films as active infrared shutters," Magister Other Engineering and Technologies, The Department of Physics, Chemistry and Biology, Linköping University, Institutionen för fysik, 2006.
[31] V. Eyert, "The metal-insulator transitions of VO2: A band theoretical approach," Annalen der Physik, vol. 11, pp. 650-704, 2002.
[32] S. Shin, S. Suga, M. Taniguchi, M. Fujisawa, H. Kanzaki, A. Fujimori, et al., "Vacuum-ultraviolet reflectance and photoemission study of the metal-insulator phase transitions in VO2, V6O13, and V2O3," Physical Review B, vol. 41, pp. 4993-5009, 1990.
[33] J. B. Goodenough, "The two components of the crystallographic transition in VO2," Journal of Solid State Chemistry, vol. 3, pp. 490-500, 1971.
[34] Y. Wu, L. Fan, W. Huang, S. Chen, S. Chen, F. Chen, et al., "Depressed transition temperature of WxV1-xO2: mechanistic insights from the X-ray absorption fine structure (XAFS) spectroscopy," Physical Chemistry Chemical Physics, vol. 16, pp. 17705-17714, 2014.
[35] E. Strelcov, A. Tselev, I. Ivanov, J. D. Budai, J. Zhang, J. Z. Tischler, et al., "Doping-Based Stabilization of the M2 Phase in Free-Standing VO2 Nanostructures at Room Temperature," Nano Letters, vol. 12, pp. 6198-6205, 2012.
[36] M. Marezio, D. B. McWhan, J. P. Remeika, and P. D. Dernier, "Structural Aspects of the Metal-Insulator Transitions in Cr-Doped VO2," Physical Review B, vol. 5, pp. 2541-2551, 1972.
[37] C. Leroux, G. Nihoul, and G. Van Tendeloo, "From VO2(B) to VO2(R): Theoretical structures of VO2 polymorphs and in situ electron microscopy," Physical Review B, vol. 57, pp. 5111-5121, 1998.
[38] Q. Zhao, L. Jiao, W. Peng, H. Gao, J. Yang, Q. Wang, et al., "Facile synthesis of VO2(B)/carbon nanobelts with high capacity and good cyclability," Journal of Power Sources, vol. 199, pp. 350-354, 2012.
[39] Y. Oka, S. Sato, T. Yao, and N. Yamamoto, "Crystal Structures and Transition Mechanism of VO2(A)," Journal of Solid State Chemistry, vol. 141, pp. 594-598, 1998.
[40] S. R. Popuri, M. Miclau, A. Artemenko, C. Labrugere, A. Villesuzanne, and M. Pollet, "Rapid Hydrothermal Synthesis of VO2 (B) and Its Conversion to Thermochromic VO2 (M1)," Inorganic Chemistry, vol. 52, pp. 4780-4785, 2013.
[41] F. Guinneton, L. Sauques, J. C. Valmalette, F. Cros, and J. R. Gavarri, "Comparative study between nanocrystalline powder and thin film of vanadium dioxide VO2: electrical and infrared properties," Journal of Physics and Chemistry of Solids, vol. 62, pp. 1229-1238, 2001.
[42] Y. Oka, T. Yao, and N. Yamamoto, "Structural phase transition of VO2(B) to VO2(A)," Journal of Materials Chemistry, vol. 1, pp. 815-818, 1991.
[43] S. Rao Popuri, A. Artemenko, C. Labrugere, M. Miclau, A. Villesuzanne, and M. Pollet, "VO2 (A): Reinvestigation of crystal structure, phase transition and crystal growth mechanisms," Journal of Solid State Chemistry, vol. 213, pp. 79-86, 2014.
[44] A. Cavalleri, C. Tóth, C. W. Siders, J. A. Squier, F. Ráksi, P. Forget, et al., "Femtosecond Structural Dynamics in VO2 during an Ultrafast Solid-Solid Phase Transition," Physical Review Letters, vol. 87, p. 237401, 2001.
[45] L. O. Chua, "Memristor—The Missing Circuit Element," IEEE Transactions on Circuit Theory, vol. 18, pp. 507-519, 1971.
[46] S. Hormoz and S. Ramanathan, "Limits on vanadium oxide Mott metal–insulator transition field-effect transistors," Solid-State Electronics, vol. 54, pp. 654-659, 2010.
[47] H. N. S. Krishnamoorthy, Y. Zhou, S. Ramanathan, E. Narimanov, and V. M. Menon, "Tunable hyperbolic metamaterials utilizing phase change heterostructures," Applied Physics Letters, vol. 104, p. 121101, 2014.
[48] L. A. Sweatlock and K. Diest, "Vanadium dioxide based plasmonic modulators," Optics Express, vol. 20, pp. 8700-8709, 2012.
[49] A. Subrahmanyam, Y. B. K. Reddy, and C. L. Nagendra, "Nano-vanadium oxide thin films in mixed phase for microbolometer applications," Journal of Physics D: Applied Physics, vol. 41, p. 195108, 2008.
[50] A. Zylbersztejn and N. F. Mott, "Metal-insulator transition in vanadium dioxide," Physical Review B, vol. 11, pp. 4383-4395, 1975.
[51] N. F. Mott and L. Friedman, "Metal-insulator transitions in VO2, Ti2O3 and Ti2-x V x O3," Philosophical Magazine, vol. 30, pp. 389-402, 1974.
[52] A. A. Akande, K. E. Rammutla, T. Moyo, N. S. E. Osman, S. S. Nkosi, C. J. Jafta, et al., "Magnetism variations and susceptibility hysteresis at the metal-insulator phase transition temperature of VO2 in a composite film containing vanadium and tungsten oxides," Journal of Magnetism and Magnetic Materials, vol. 375, pp. 1-9, 2015.
[53] J. B. Goodenough, "Direct Cation- -Cation Interactions in Several Oxides," Physical Review, vol. 117, pp. 1442-1451, 1960.
[54] D. Adler and H. Brooks, "Theory of Semiconductor-To-Metal Transitions," Physical Review, vol. 155, pp. 826-840, 1967.
[55] P. Baum, D.-S. Yang, and A. H. Zewail, "4D Visualization of Transitional Structures in Phase Transformations by Electron Diffraction," Science, vol. 318, pp. 788-792, 2007.
[56] M. M. Qazilbash, M. Brehm, B.-G. Chae, P.-C. Ho, G. O. Andreev, B.-J. Kim, et al., "Mott Transition in VO2 Revealed by Infrared Spectroscopy and Nano-Imaging," Science, vol. 318, pp. 1750-1753, 2007.
[57] Y.-B. Kang, "Critical evaluation and thermodynamic optimization of the VO–VO2.5 system," Journal of the European Ceramic Society, vol. 32, pp. 3187-3198, 2012.
[58] G. A. Thomas, D. H. Rapkine, S. A. Carter, A. J. Millis, T. F. Rosenbaum, P. Metcalf, et al., "Observation of the Gap and Kinetic Energy in a Correlated Insulator," Physical Review Letters, vol. 73, pp. 1529-1532, 1994.
[59] M. Foëx, "Chimie physique-etude dilatometrique et electrique de lanomalie, presentee a basse temperature, par le sesquioxyde de vanadium," Comptes Rendus de l'Académie des Sciences, vol. 223, pp. 1126-1128, 1946.
[60] D. B. McWhan, T. M. Rice, and J. P. Remeika, "Mott Transition in Cr-Doped V2O3," Physical Review Letters, vol. 23, pp. 1384-1387, 1969.
[61] M. Imada, A. Fujimori, and Y. Tokura, "Metal-insulator transitions," Reviews of Modern Physics, vol. 70, pp. 1039-1263, 1998.
[62] A. Chakrabarti, K. Hermann, R. Druzinic, M. Witko, F. Wagner, and M. Petersen, "Geometric and electronic structure of vanadium pentoxide: A density functional bulk and surface study," Physical Review B, vol. 59, pp. 10583-10590, 1999.
[63] A. Magnéli, "The Crystal Structures of Mo9O26 (Beta'-Molybdenum Oxide) and MO8O23 (Beta-Molybdenum Oxide)," Acta Chemica Scandinavica, vol. 2, pp. 501-517, 1948.
[64] U. Schwingenschlögl and V. Eyert, "The vanadium Magnéli phases VnO2n-1," Annalen der Physik, vol. 13, pp. 475-510, 2004.
[65] H. Katzke, P. Tolédano, and W. Depmeier, "Theory of morphotropic transformations in vanadium oxides," Physical Review B, vol. 68, p. 024109, 2003.
[66] S. Kachi, K. Kosuge, and H. Okinaka, "Metal-insulator transition in VnO2n−1," Journal of Solid State Chemistry, vol. 6, pp. 258-270, 1973.
[67] !!! INVALID CITATION !!! .
[68] W. Van Hove, P. Clauws, and J. Vennik, "Optical properties of V6O13 single crystals in the metallic and the semiconducting phase," Solid State Communications, vol. 33, pp. 11-16, 1980.
[69] C. Julien, G. A. Nazri, and O. Bergström, "Raman Scattering Studies of Microcrystalline V6O13," physica status solidi (b), vol. 201, pp. 319-326, 1997.
[70] Y. Zhou, Y. Cai, X. Hu, and Y. Long, "VO2/hydrogel hybrid nanothermochromic material with ultra-high solar modulation and luminous transmission," Journal of Materials Chemistry A, vol. 3, pp. 1121-1126, 2015.
[71] S. M. Babulanam, T. S. Eriksson, G. A. Niklasson, and C. G. Granqvist, "Thermochromic VO2 Films for Energy-Efficient Windows," in Materials and Optics for Solar Energy Conversion and Advanced Lightning Technology, San Diego, 1987, pp. 8-18.
[72] G. Xu, P. Jin, M. Tazawa, and K. Yoshimura, "Thickness dependence of optical properties of VO2 thin films epitaxially grown on sapphire (0 0 0 1)," Applied Surface Science, vol. 244, pp. 449-452, 2005.
[73] H. Kim, N. Charipar, M. Osofsky, S. B. Qadri, and A. Piqué, "Optimization of the semiconductor-metal transition in VO2 epitaxial thin films as a function of oxygen growth pressure," Applied Physics Letters, vol. 104, p. 081913, 2014.
[74] J. Y. Suh, R. Lopez, L. C. Feldman, and R. F. Haglund Jr., "Semiconductor to metal phase transition in the nucleation and growth of VO2 nanoparticles and thin films," Journal of Applied Physics, vol. 96, pp. 1209-1213, 2004.
[75] G. A. Nyberg and R. A. Buhrman, "Summary Abstract: Preparation and optical properties of reactively evaporated VO2 thin films," Journal of Vacuum Science & Technology A, vol. 2, pp. 301-302, 1984.
[76] Y. Muraoka and Z. Hiroi, "Metal–insulator transition of VO2 thin films grown on TiO2 (001) and (110) substrates," Applied Physics Letters, vol. 80, pp. 583-585, 2002.
[77] W. Haidinger and D. Gross, "Anomalous hysteresis shape of thin VO2 layers," Thin Solid Films, vol. 12, pp. 433-438, 1972.
[78] S. Kittiwatanakul, J. Laverock, D. Newby, K. E. Smith, S. A. Wolf, and J. Lu, "Transport behavior and electronic structure of phase pure VO2 thin films grown on c-plane sapphire under different O2 partial pressure," Journal of Applied Physics, vol. 114, p. 053703, 2013.
[79] M.-H. Lee and M.-G. Kim, "RTA and stoichiometry effect on the thermochromism of VO2 thin films," Thin Solid Films, vol. 286, pp. 219-222, 1996.
[80] D.-p. Zhang, M.-d. Zhu, Y. Liu, K. Yang, G.-x. Liang, Z.-h. Zheng, et al., "High performance VO2 thin films growth by DC magnetron sputtering at low temperature for smart energy efficient window application," Journal of Alloys and Compounds, vol. 659, pp. 198-202, 2016.
[81] F. C. Case, "Modifications in the phase transition properties of predeposited VO2 films," Journal of Vacuum Science & Technology A, vol. 2, pp. 1509-1512, 1984.
[82] P. Jin, S. Nakao, S. Tanemura, T. Bell, L. S. Wielunski, and M. V. Swain, "Characterization of mechanical properties of VO2 thin films on sapphire and silicon by ultra-microindentation," Thin Solid Films, vol. 343, pp. 134-137, 1999.
[83] T. Lin, L. Wang, X. Wang, Y. Zhang, and Y. Yu, "Influence of lattice distortion on phase transition properties of polycrystalline VO2 thin film," Applied Surface Science, vol. 379, pp. 179-185, 2016.
[84] G. Villeneuve, A. Bordet, A. Casalot, and P. Hagenmuller, "Proprietes physiques et structurales de la phase CrxV1−xO2," Materials Research Bulletin, vol. 6, pp. 119-130, 1971.
[85] E. Pollert, G. Villeneuve, F. Ménil, and P. Hagenmuller, "Le systeme V1−xFexO2: Proprietes structurales et magnetiques," Materials Research Bulletin, vol. 11, pp. 159-166, 1976.
[86] J. Pouget and H. Launois, "Metal-insulator phase transition in VO2," Le Journal de Physique Colloques, vol. 37, pp. C4-49-C4-57, 1976.
[87] F. Béteille and J. Livage, "Optical Switching in VO2 Thin Films," Journal of Sol-Gel Science and Technology, vol. 13, pp. 915-921, 1998.
[88] N. R. Mlyuka, G. A. Niklasson, and C. G. Granqvist, "Mg doping of thermochromic VO2 films enhances the optical transmittance and decreases the metal-insulator transition temperature," Applied Physics Letters, vol. 95, p. 171909, 2009.
[89] S. Lu, L. Hou, and F. Gan, "Synthesis and phase transition of Cu2+ ion doped VO2 thin films," Journal of Materials Science Letters, vol. 15, pp. 856-857, 1996.
[90] M. H. Lee, M. G. Kim, and H. K. Song, "Thermochromism of rapid thermal annealed VO2 and Sn-doped VO2 thin films," Thin Solid Films, vol. 290-291, pp. 30-33, 1996.
[91] J. B. MacChesney and H. J. Guggenheim, "Growth and electrical properties of vanadium dioxide single crystals containing selected impurity ions," Journal of Physics and Chemistry of Solids, vol. 30, pp. 225-234, 1969.
[92] T. E. Phillips, R. A. Murphy, and T. O. Poehler, "Electrical studies of reactively sputtered Fe-doped VO2 thin films," Materials Research Bulletin, vol. 22, pp. 1113-1123, 1987.
[93] X. Cao, N. Wang, S. Magdassi, D. Mandler, and Y. Long, "Europium doped vanadium dioxide material: Reduced phase transition temperature, enhanced luminous transmittance and solar modulation," Science of Advanced Materials, vol. 6, pp. 558-561, 2014.
[94] D. Gu, Z. Sun, X. Zhou, R. Guo, T. Wang, and Y. Jiang, "Effect of yttrium-doping on the microstructures and semiconductor-metal phase transition characteristics of polycrystalline VO2 thin films," Applied Surface Science, vol. 359, pp. 819-825, 2015.
[95] J. Du, Y. Gao, H. Luo, L. Kang, Z. Zhang, Z. Chen, et al., "Significant changes in phase-transition hysteresis for Ti-doped VO2 films prepared by polymer-assisted deposition," Solar Energy Materials and Solar Cells, vol. 95, pp. 469-475, 2011.
[96] Ö. Sävborg and M. Nygren, "Magnetic, electrical, and thermal studies of the V1−xRexO2 system with 0 ≦ x ≦ 0.15," physica status solidi (a), vol. 43, pp. 645-652, 1977.
[97] C. Batista, R. M. Ribeiro, and V. Teixeira, "Synthesis and characterization of VO2-based thermochromic thin films for energy-efficient windows," Nanoscale Research Letters, vol. 6, pp. 1-7, 2011.
[98] C. Piccirillo, R. Binions, and I. P. Parkin, "Nb-Doped VO2 Thin Films Prepared by Aerosol-Assisted Chemical Vapour Deposition," European Journal of Inorganic Chemistry, vol. 2007, pp. 4050-4055, 2007.
[99] J. Li, N. Yuan, T. Xie, and D. Dan, "Influence of Ta doping on the phase transition characteristics of VO2 polycrystalline thin films," in 2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, 2006, pp. 61490B-61490B-5.
[100] T. J. Hanlon, J. A. Coath, and M. A. Richardson, "Molybdenum-doped vanadium dioxide coatings on glass produced by the aqueous sol-gel method," Thin Solid Films, vol. 436, pp. 269-272, 2003.
[101] Y. Jiazhen, Z. Yue, H. Wanxia, and T. Mingjin, "Effect of Mo-W Co-doping on semiconductor-metal phase transition temperature of vanadium dioxide film," Thin Solid Films, vol. 516, pp. 8554-8558, 2008.
[102] F. Y. Kong, M. Li, S. S. Pan, Y. X. Zhang, and G. H. Li, "Synthesis and thermal stability of W-doped VO2 nanocrystals," Materials Research Bulletin, vol. 46, pp. 2100-2104, 2011.
[103] M. A. Sobhan, R. T. Kivaisi, B. Stjerna, and C. G. Granqvist, "Thermochromism of sputter deposited WxV1−xO2 films," Solar Energy Materials and Solar Cells, vol. 44, pp. 451-455, 1996.
[104] Y. Zhang, W. Li, M. Fan, F. Zhang, J. Zhang, X. Liu, et al., "Preparation of W- and Mo-doped VO2(M) by ethanol reduction of peroxovanadium complexes and their phase transition and optical switching properties," Journal of Alloys and Compounds, vol. 544, pp. 30-36, 2012.
[105] Y. Ningyi, L. Jinhua, and L. Chenglu, "Valence reduction process from sol–gel V2O5 to VO2 thin films," Applied Surface Science, vol. 191, pp. 176-180, 2002.
[106] B. G. Chae, H. T. Kim, and S. J. Yun, "Characteristics of W- and Ti-Doped VO2 Thin Films Prepared by Sol-Gel Method," Electrochemical and Solid-State Letters, vol. 11, pp. D53-D55, 2008.
[107] J.-H. Cho, Y.-J. Byun, J.-H. Kim, Y.-J. Lee, Y.-H. Jeong, M.-P. Chun, et al., "Thermochromic characteristics of WO3-doped vanadium dioxide thin films prepared by sol–gel method," Ceramics International, vol. 38, Supplement 1, pp. S589-S593, 2012.
[108] X. Liu, C. Huang, S. Yi, G. Xie, H. Li, and Y. Luo, "A new solvothermal method of preparing VO2 nanosheets and petaloid clusters," Solid State Communications, vol. 144, pp. 259-263, 2007.
[109] R. Minch and M. Es-Souni, "Nanostructured VO2 thin films via cathodic deposition," CrystEngComm, vol. 15, pp. 6645-6647, 2013.
[110] T. D. Manning, I. P. Parkin, R. J. H. Clark, D. Sheel, M. E. Pemble, and D. Vernadou, "Intelligent window coatings: atmospheric pressure chemical vapour deposition of vanadium oxides," Journal of Materials Chemistry, vol. 12, pp. 2936-2939, 2002.
[111] T. D. Manning, I. P. Parkin, M. E. Pemble, D. Sheel, and D. Vernardou, "Intelligent Window Coatings:  Atmospheric Pressure Chemical Vapor Deposition of Tungsten-Doped Vanadium Dioxide," Chemistry of Materials, vol. 16, pp. 744-749, 2004.
[112] C. Piccirillo, R. Binions, and I. P. Parkin, "Synthesis and Functional Properties of Vanadium Oxides: V2O3, VO2, and V2O5 Deposited on Glass by Aerosol-Assisted CVD," Chemical Vapor Deposition, vol. 13, pp. 145-151, 2007.
[113] M. E. A. Warwick and R. Binions, "Thermochromic vanadium dioxide thin films from electric field assisted aerosol assisted chemical vapour deposition," Solar Energy Materials and Solar Cells, vol. 143, pp. 592-600, 2015.
[114] M. Ranjbar, S. M. Mahdavi, and A. Iraji zad, "Pulsed laser deposition of W–V–O composite films: Preparation, characterization and gasochromic studies," Solar Energy Materials and Solar Cells, vol. 92, pp. 878-883, 2008.
[115] A. Kaushal, N. Choudhary, N. Kaur, and D. Kaur, "VO2–WO3 nanocomposite thin films synthesized by pulsed laser deposition technique," Applied Surface Science, vol. 257, pp. 8937-8944, 2011.
[116] S. Lee, I. N. Ivanov, J. K. Keum, and H. N. Lee, "Epitaxial stabilization and phase instability of VO2 polymorphs," Scientific Reports, vol. 6, p. 19621, 2016.
[117] G. Rampelberg, M. Schaekers, K. Martens, Q. Xie, D. Deduytsche, B. De Schutter, et al., "Semiconductor-metal transition in thin VO2 films grown by ozone based atomic layer deposition," in 11th International conference on Atomic Layer Deposition (ALD 2011), 2011.
[118] R. Marvel, K. Appavoo, B. Choi, J. Nag, and R. Haglund, "Electron-beam deposition of vanadium dioxide thin films," Applied Physics A: Materials Science & Processing, vol. 111, pp. 975-981, 2013.
[119] F. C. Case, "Reactive evaporation of anomalous blue VO2," Applied Optics, vol. 26, pp. 1550-1553, 1987.
[120] J. Leroy, A. Bessaudou, F. Cosset, and A. Crunteanu, "Structural, electrical and optical properties of thermochromic VO2 thin films obtained by reactive electron beam evaporation," Thin Solid Films, vol. 520, pp. 4823-4825, 2012.
[121] Z. Huang, C. Chen, C. Lv, and S. Chen, "Tungsten-doped vanadium dioxide thin films on borosilicate glass for smart window application," Journal of Alloys and Compounds, vol. 564, pp. 158-161, 2013.
[122] A. Paone, R. Sanjines, P. Jeanneret, and A. Schüler, "Temperature-dependent multiangle FTIR NIR–MIR ellipsometry of thermochromic VO2 and V1−xWxO2 films," Solar Energy, vol. 118, pp. 107-116, 2015.
[123] H. Zhou, J. Li, S. Bao, J. Li, X. Liu, and P. Jin, "Use of ZnO as antireflective, protective, antibacterial, and biocompatible multifunction nanolayer of thermochromic VO2 nanofilm for intelligent windows," Applied Surface Science, vol. 363, pp. 532-542, 2016.
[124] J. B. MacChesney, J. F. Potter, and H. J. Guggenheim, "Preparation and Properties of Vanadium Dioxide Films," Journal of The Electrochemical Society, vol. 115, pp. 52-55, 1968.
[125] G. Greczynski and L. Hultman, "C 1s Peak of Adventitious Carbon Aligns to the Vacuum Level: Dire Consequences for Material's Bonding Assignment by Photoelectron Spectroscopy," ChemPhysChem, pp. n/a-n/a, 2017.
[126] Y. M. Chiang, D. P. Birnie, and W. D. Kingery, Physical Ceramics: Principles for Ceramic Science and Engineering: Wiley, 1996.
[127] M. Ghanashyam Krishna, Y. Debauge, and A. K. Bhattacharya, "X-ray photoelectron spectroscopy and spectral transmittance study of stoichiometry in sputtered vanadium oxide films," Thin Solid Films, vol. 312, pp. 116-122, 1998.
[128] J. Cui, D. Da, and W. Jiang, "Structure characterization of vanadium oxide thin films prepared by magnetron sputtering methods," Applied Surface Science, vol. 133, pp. 225-229, 1998.
[129] G. A. Sawatzky and D. Post, "X-ray photoelectron and Auger spectroscopy study of some vanadium oxides," Physical Review B, vol. 20, pp. 1546-1555, 1979.
[130] F. Gracia, F. Yubero, J. P. Espinós, and A. R. González-Elipe, "First nucleation steps of vanadium oxide thin films studied by XPS inelastic peak shape analysis," Applied Surface Science, vol. 252, pp. 189-195, 2005.
[131] B. Blackburn, M. J. Powell, C. E. Knapp, J. C. Bear, C. J. Carmalt, and I. P. Parkin, "[{VOCl2(CH2(COOEt)2)}4] as a molecular precursor for thermochromic monoclinic VO2 thin films and nanoparticles," Journal of Materials Chemistry C, vol. 4, pp. 10453-10463, 2016.
[132] H. Yoon, M. Choi, T.-W. Lim, H. Kwon, K. Ihm, J. K. Kim, et al., "Reversible phase modulation and hydrogen storage in multivalent VO2 epitaxial thin films," Nature Materials, vol. 15, pp. 1113-1119, 2016.
[133] Z. Zhang, Y. Gao, Z. Chen, J. Du, C. Cao, L. Kang, et al., "Thermochromic VO2 Thin Films: Solution-Based Processing, Improved Optical Properties, and Lowered Phase Transformation Temperature," Langmuir, vol. 26, pp. 10738-10744, 2010.
[134] J. P. Fortier, B. Baloukas, O. Zabeida, J. E. Klemberg-Sapieha, and L. Martinu, "Thermochromic VO2 thin films deposited by HiPIMS," Solar Energy Materials and Solar Cells, vol. 125, pp. 291-296, 2014.
[135] L. Kang, Y. Gao, H. Luo, Z. Chen, J. Du, and Z. Zhang, "Nanoporous Thermochromic VO2 Films with Low Optical Constants, Enhanced Luminous Transmittance and Thermochromic Properties," ACS Applied Materials & Interfaces, vol. 3, pp. 135-138, 2011.
[136] N. R. Mlyuka, G. A. Niklasson, and C. G. Granqvist, "Thermochromic multilayer films of VO2 and TiO2 with enhanced transmittance," Solar Energy Materials and Solar Cells, vol. 93, pp. 1685-1687, 2009.
[137] Z. Zhang, Y. Gao, H. Luo, L. Kang, Z. Chen, J. Du, et al., "Solution-based fabrication of vanadium dioxide on F:SnO2 substrates with largely enhanced thermochromism and low-emissivity for energy-saving applications," Energy & Environmental Science, vol. 4, pp. 4290-4297, 2011.
[138] P. Evans, M. E. Pemble, D. W. Sheel, and H. M. Yates, "Multi-functional self-cleaning thermochromic films by atmospheric pressure chemical vapour deposition," Journal of Photochemistry and Photobiology A: Chemistry, vol. 189, pp. 387-397, 2007.
[139] G. Xu, P. Jin, M. Tazawa, and K. Yoshimura, "Optimization of antireflection coating for VO2-based energy efficient window," Solar Energy Materials and Solar Cells, vol. 83, pp. 29-37, 2004.
[140] J. Ye, L. Zhou, F. Liu, J. Qi, W. Gong, Y. Lin, et al., "Preparation, characterization and properties of thermochromic tungsten-doped vanadium dioxide by thermal reduction and annealing," Journal of Alloys and Compounds, vol. 504, pp. 503-507, 2010.
[141] S. Zhou, Y. Li, H. Zhu, R. Sun, Y. Zhang, Y. Huang, et al., "Microstructures and thermochromic characteristics of low-cost vanadium–tungsten co-sputtered thin films," Surface and Coatings Technology, vol. 206, pp. 2922-2926, 2012.
[142] X. Tan, T. Yao, R. Long, Z. Sun, Y. Feng, H. Cheng, et al., "Unraveling Metal-insulator Transition Mechanism of VO2 Triggered by Tungsten Doping," Scientific Reports, vol. 2, p. 466, 2012.
[143] R. D. Shannon, "Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides," Acta Crystallographica Section A, vol. 32, pp. 751-767, 1976.
[144] J. Nii, "Phase Diagram of the VO2-WO2-WO3 System at 1173K and 1373K," 三重大学教育学部研究紀要. 自然科学, vol. 36, pp. 47-52, 1985.
[145] Bruker-Corporation. (2017). Periodic Table of Elements and X-ray Energies. Available: https://www.bruker.com/fileadmin/user_upload/8-PDF-Docs/X-rayDiffraction_ElementalAnalysis/HH-XRF/Misc/Periodic_Table_and_X-ray_Energies.pdf
[146] X. He, Y. Zeng, X. Xu, C. Gu, F. Chen, B. Wu, et al., "Orbital change manipulation metal-insulator transition temperature in W-doped VO2," Physical Chemistry Chemical Physics, vol. 17, pp. 11638-11646, 2015.