A thermochromic low-emittance coating: Calculations for nanocomposites of In2O3:Sn and VO2

Calculations based on the Bruggeman effective medium theory were applied to thin films comprising a heavily doped wide band gap semiconductor (specifically In2O3:Sn (ITO)) and VO2. Films with similar to 20 vol. % of VO2 can combine a 10% thermochromic modulation of the solar energy throughput with a luminous transmittance of 50%-60% and low thermal emittance. The maximum thermochromic modulation is similar to 13% and occurs at similar to 35 vol. % VO2. Coatings of ITO-VO2 are of interest for energy efficient fenestration. (C) 2011 American Institute of Physics. [doi:10.1063/1.3641869]