Preparation and electrochromic properties of indium tin oxide nanocrystal films

Abstract

Indium tin oxide (ITO) nanocrystals with different shapes and sizes were synthesized by one-pot method, and ITO nanocrystal films were prepared by spin-coating process. The near-infrared spectrum regulation properties of the films prepared by ITO nanocrystals with different morphologies and sizes were studied. The results show that the visible light transmittance of ITO nanocrystal film is 89.2%, and the resistivity is 54 Ω·cm after 5 spin coatings. The films prepared by uniform spherical ITO nanocrystals with an average diameter of (6.88±1.53) nm exhibit the best near-infrared spectrum regulation ability. After applying a voltage of ±2.5 V, the spectrum regulation at 2000 nm is 39.3%, and the optical density change is 0.43. The ITO nanocrystal film maintains high visible light transmittance before and after electrochromism. The electrochromism of ITO nanocrystals is caused by change of frequency and intensity of localized surface plasmon resonance(LSPR) caused by electron injection/extraction, and its electrochromic process is realized by capacitor charging and discharging.

Keywords

• indium tin oxide
• electrochromism
• nanocrystal film
• smart window