Porous W-doped VO2 films with simultaneously enhanced visible transparency and thermochromic properties

Journal of Sol-Gel Science and Technology - Tập 77 - Trang 85-93 - 2015
Lingting Hu1, Haizheng Tao1, Guohua Chen2, Ruikun Pan1, Meinan Wan1, Dehua Xiong1, Xiujian Zhao1
1State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, China
2Guangxi Key Laboratory of Information Materials, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, China

Tóm tắt

Porous thermochromic pure and tungsten (W)-doped vanadium dioxide (VO2) films have been prepared on silica substrates by spin coating via a sol–gel process and annealing in ammonia (NH3) atmosphere. NH3 with weak reducing capacity can prevent V4+ from further oxidization and contribute to the formation of porous structure. These films exhibit enhanced visible transparency and switching property at near-infrared wavelengths across the metal–insulator transition (MIT). The transmittance change in the VO2 film annealed at 2.0 × 103Pa is as high as 52.9 % at λ = 2000 nm, and its solar modulation efficiency reaches up to 9.4 %. W-doping shifts the MIT temperature of the VO2 films from 55 to 28 °C, while the films remain the excellent modulating ability in near-infrared region, and the decreasing efficiency of V0.99W0.01O2 film can achieve to 20 K/at.%, which will greatly favor the practical application of VO2-based smart windows. Transmittance spectra for pure VO2 film in the range of 250–2500 nm and the recorded transmittance–temperature hysteresis loop in the range of 20–90 °C of the W-doping VO2 films after annealing at 500 °C for 30 min (middle inset).

Tài liệu tham khảo

Morin FJ (1959) Oxides which show a metal-to-insulator transition at the neel temperature. Phys Rev Lett 3:34–36 Cao X, Wang N, Law JY, Loo SCJ, Magdassi S, Long Y (2014) Nanoporous thermochromic VO2 (M) thin films: controlled porosity, largely enhanced luminous transmittance and solar modulating ability. Langmuir 30:1710–1715 Zhao L, Miao L, Tanemura S, Zhou J, Chen L, Xiao X, Xu G (2013) A low cost preparation of VO2 thin films with improved thermochromic properties from a solution-based process. Thin Solid Films 543:157–161 Zhang Z, Gao Y, Luo H, Kang L, Chen Z, Du J, Kanehira M, Zhang Y, Wang ZL (2013) Solution-based fabrication of vanadium dioxide on F: SnO2 substrates with largely enhanced thermochromism and low-emissivity for energy-saving applications. J Energy Environ Sci 4:4290–4297 Zhang Z, Gao Y, Chen Z, Du J, Cao C, Kang L, Lou H (2010) Thermochromic VO2 thin films: solution-based processing, improved optical properties, and lowered phase transformation temperature. Langmuir 26:10738–10744 Mlyuka NR, Niklasson NR, Granqvist CG (2009) Mg doping of thermochromic VO2 films enhances the optical transmittance and decreases the metal-insulator transition temperature. Appl Phys Lett 95:171909–171912 Burkhardt W, Christmann W, Franke S, Kriegseis W, Meister D, Meyer BK, Niessner W, Schalch D (2002) A. scharmann, tungsten and fluorine co-doping of VO2 films. Thin Solid Films 402:226–231 Gao Y, Wang S, Luo H, Dai L, Cao C, Liu Y, Chen Z, Kanehira M (2012) Enhanced chemical stability of VO2 nanoparticles by the formation of SiO2/VO2 core/shell structures and the application to transparent and flexible VO2-based composite foils with excellent thermochromic properties for solar heat control. J Energy Environ Sci 5:6104–6110 Chen HK, Hung HC, Yang TCK, Wang SF (2004) The preparation and characterization of transparent nano-sized thermochromic VO2–SiO2 films from the sol–gel process. J Non-Cryst Solids 347:138–143 Lee MH, Cho JS (2000) Better thermochromic glazing of windows with anti-reflection coating. Thin Solid Films 365:5–6 Jin P, Xu P, Tazawa M, Yoshimura K (2003) Design, formation and characterization of a novel multifunctional window with VO2 and TiO2 coatings. J Appl Phys A 77:455–459 Mlyuka NR, Niklasson GA, Granqvist GA (2009) Thermochromic VO2 based multilayer films with enhanced luminous transmittance and solar modulation. Phys Status Solidi A 206:2155–2160 Kang L, Gao Y, Luo H, Chen Z, Du J, Zhang Z (2011) Nanoporous thermochromic VO2 films with low optical constants, enhanced luminous transmittance and thermochromic properties. ACS Appl Mater Inter 3:135–138 Zhou M, Bao J, Tao M, Zhu R, Lin Y, Zhang X, Xie Y (2013) Periodic porous thermochromic VO2(M) films with enhanced visible transmittance. Chem Commu 49:6021–6023 Shibuya K, Kawasaki M, Tokura Y (2010) Metal-insulator transition in epitaxial V1−xWxO2 (0 ≤ x ≤ 0.33) thin films. Appl Phys Lett 96:022102–022105 Kang Y, Gao Y, Zhang Z, Du J, Cao C, Chen Z, Luo H (2010) Effects of annealing parameters on optical properties of thermochromic VO2 films prepared in aqueous solution. J Phys Chem C 114:1901–1911 Zhang Z, Gao Y, Kang Y, Du J, Luo H (2010) Effects of a TiO2 buffer layer on solution-deposited VO2 films: enhanced oxidization durability. J Phys Chem 114:22214–22220 Kang L, Gao Y, Luo H (2011) VO2 films by polymer-assisted deposition: investigation of thermal decomposition of precursor gel and control of phase transition temperatures. Mater Sci Forum 687:791–797 Glushenkov AM, Hulicova-Jurcakova D, Llewellyn D, Lu GQ, Chen Y (2009) Structure and capacitive properties of porous nanocrystalline vn prepared by temperature-programmed ammonia reduction of V2O5†. Chem Mater 22:914–921 Hayashi F, Tomota Y, Kitano M, Toda Y, Yokoyama T, Hosono H (2014) NH2−dianion entrapped in a nanoporous 12CaO·7Al2O3 crystal by ammonothermal treatment: reaction pathways, dynamics, and chemical stability. J Am Chem Soc 136:11698–11706 Li J, Dho J (2011) Anomalous optical switching and thermal hysteresis behaviors of VO2 films on glass substrate. Appl Phys Lett 99:231909 Shi Q, Huang W, Zhang Y, Qiao S, Wu J, Zhao D, Yan J (2012) Enhanced hydrophilicity of the Si substrate for deposition of VO2 film by sol–gel method. J Mat Sci Mat Elect 23:1610–1615 Shen N, Li Y, Yi X (2006) Preparation of VO2 films with nanostructure and improvement on its visible transmittance. J Infrared Millim W 25:199–202 Lopez R, Haynes TE, Boatner LA, Feldman LC, Haglund RF (2002) Size effects in the structural phase transition of VO2 nanoparticles. Phys Rev B 65:224113 Chen Z, Gao Z, Kang L, Cao C, Chen S, Luo H (2014) Fine crystalline VO2 nanoparticles: synthesis, abnormal phase transition temperatures and excellent optical properties of a derived VO2 nanocomposite foil. J Mater Chem A 2:2718–2727 Sun Y, Xiao X, Xu G, Dong G, Chai G, Zhang H, Liu P, Zhu H, Zhan Y (2013) Anisotropic vanadium dioxide sculptured thin films with superior thermochromic properties. Sci Rep 3:2756–2766 Du J, Gao Y, Luo H, Kang L, Zhang Z, Chen Z, Cao C (2011) Significant changes in phase-transition hysteresis for Ti-doped VO2 films prepared by polymer-assisted deposition. Sol Energy Mater Sol C 95:469–475 Patridge CJ, Whittaker L, Ravel B, Banerjee S (2012) Elucidating the influence of local structure perturbations on the metal-insulator transitions of V1−xMoxO2 nanowires: mechanistic insights from an x-ray absorption spectroscopy study. J Phys Chem C 116:3728–3736 Jin P, Nakao P, Tanemura S (1998) Tungsten doping into vanadium dioxide thermochromic films by high-energy ion implantation and thermal annealing. Thin Solid Films 324:151–158