APPLICATIONS OF TECHNOLOGY:
- Smart windows
- Vehicle glass
- Thermal control coatings for satellites
- Infrared displays
- Faster switching speed
- Higher coloration efficiency
- Highly selective infrared modulation
- Longer lifetime
- Inexpensive, non toxic, earth-abundant material
- Solution processing for low-cost deposition
Scientists at Berkeley Lab have developed a nanostructured electrochromic device that maintains visible transparency while varying the transmission of near infrared radiation. The device incorporates a film made of transparent conducting oxide (TCO) nanostructures, specifically tin-doped indium oxide (ITO) or aluminum-doped zinc oxide (AZO). The film is either supported by a substrate of glass or other materials, or embedded in an electrolyte and positioned between the substrate and a counter electrode. By having a higher surface area than existing thin films, this technology enables faster switching speed for more efficient electrochromic windows.
Earlier attempts to develop nanostructured electrochromic devices focused on toxic and expensive materials such as antimony-doped tin oxide, or materials lacking infrared selectivity, such as tungsten oxide.
DEVELOPMENT STAGE: Bench scale demonstration. Cyclic voltammograms of ITO and AZO particle films demonstrate a capacitive charging under applied potential. Spectro-electrochemical measurements show that transmission is strongly modulated in the near infrared. The specific wavelength of the infrared blocking shifts under a few volts of applied bias. Preliminary cycling tests have been performed.
STATUS: Patent pending. Available for licensing or collaborative research.
FOR MORE INFORMATION:
G. Garcia, R. Buonsanti, E.L. Runnerstrom, R.J. Mendelsberg, A. Llordes, A. Anders, T.J. Richardson, D.J. Milliron, “Dynamically modulating the surface plasmon resonance of doped semiconductor nanocrystals,” Nano Lett. 11 (2011), 4415.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
Universal Electrochromic Smart Window Coating, IB-3072
Modular Inorganic Nanocomposites, IB-2749
REFERENCE NUMBER: IB-2938