Thermochromic undoped and Mg-doped VO{sub 2} thin films and nanoparticles: Optical properties and performance limits for energy efficient windows

Journal Article · Fri Feb 07 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4862930· OSTI ID:22278138

Li, Shu-Yi; Niklasson, Gunnar A.; Granqvist, Claes G. ^[1]

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1. Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P.O. Box 534, SE-75121 Uppsala (Sweden)

Undoped and Mg-doped thermochromic VO{sub 2} films with atom ratios z ≡ Mg/(Mg + V) of 0 ≤ z < 0.21 were deposited by reactive DC magnetron sputtering onto heated glass and carbon substrates. Elemental compositions were found by Rutherford backscattering spectrometry. Optical constants were determined from transmittance and reflectance measurements and were used for modeling the optical properties of thin films and dilute nanoparticle composite layers below and above the critical temperature for thermochromic switching between a low-temperature infrared transparent state and a high-temperature infrared reflecting or absorbing state. Mg-doped films showed superior luminous transmittance T{sub lum} and solar transmittance modulation ΔT{sub sol} compared to undoped VO{sub 2} films, and both of these parameters could be further enhanced by anti-reflection. VO{sub 2}-containing nanocomposites had much larger values of T{sub lum} and ΔT{sub sol} than VO{sub 2}-based films. Mg-doping was found to erode the properties of the nanocomposites. Approximate performance limits are given on T{sub lum} and ΔT{sub sol} for thermochromic VO{sub 2} films, with and without Mg doping and antireflection coating, and also for VO{sub 2}-containing dilute nanocomposites.

• OSTI ID: 22278138
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMS
CARBON
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
CRITICAL TEMPERATURE
DOPED MATERIALS
GLASS
MAGNESIUM COMPOUNDS
MODULATION
NANOSTRUCTURES
OPACITY
PERFORMANCE
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SPECTRAL REFLECTANCE
SPUTTERING
SUBSTRATES
THIN FILMS
VANADIUM OXIDES