Engineering thermochromic properties with plasmonics*

Materials with thermochromic properties are useful for real-time temperature sensing, but the application of these materials requires a strong opto-thermal response on the visible spectrum. In this presentation, we show how to enhance the opto-thermal sensitivity of thermochromic materials by taking advantage of plasmonic effects. Before adding plasmonic structures, we compare compounds of vanadium oxide to determine a material with a suitable initial opto-thermal sensitivity. We subsequently evaluate temperature-dependent optical measurements taken for the materials. Finally, we present changes in the opto-thermal sensitivity achieved by the addition of plasmonic structures on the selected thermochromic material. A fifteen percent improvement was observed in the thermochromic response of thin-film vanadium dioxide crystals with self-assembled gold nanoparticles. We propose that this improvement was achievable as a result of the localized surface plasmon resonance of the self-assembled gold structures, as supported by the Maxwell Garnett effective medium theory.