Optical properties of an all-plastic WO3⋅H2O-based infrared modulator

Abstract

Articles you may be interested inInfrared-to-visible upconversion emission in Er3+ doped TeO2-WO3-Bi2O3 glasses with silver nanoparticles J. Appl. Phys. 112, 063519 (2012); 10.1063/1.4754468 Demonstration of enhanced population feeding of the 1.53 μ m emitting level of Er 3 + in Te O 2 -W O 3 -Li 2 O -P 2 O 5 glasses using upconversion luminescence spectroscopy Flexible electrochromic reflectance device based on tungsten oxide for infrared emissivity control WO 3 •H 2 O powder embedded in a plastic matrix has demonstrated attractive properties as a flexible emissivity modulator driven by the electrochemical insertion of lithium. The near infrared optical properties of Li x WO 3 •H 2 O are investigated as a function of the lithium intercalation level x for 0рxр2.65. The reflectivity at 2.5 m, measured through a glass window, was found to vary between 0.15 and 0.4 over the ␣ intercalation phase (0рxϽ0.3), i.e., demonstrating an emissivity contrast of ϳ0.25. For xу0.1 the Li x WO 3 •H 2 O-based plastic device exhibits a Drude behavior comparable to that of monoclinic tungsten oxide (m-WO 3 ) thin films. For larger intercalation levels, the performances are affected by some irreversible structural modifications of the Li x WO 3 •H 2 O lattice.

Particle Size Effect on the Electronic Conductivity of Electroactive LixWO3·H2O Powders: A Study from 103 to 1010 Hz

“…The attention in studying the electrical properties of tungsten trioxide monohydrate WO 3 ·H 2 O was stimulated by its promise as regards use as a basic compound in infrared emissivity/reflectivity flexible modulators driven by the electrochemical insertion of lithium ions. − The injection of electrons comes with the insertion of these cations in the compound. Hence, the variation in electron population can induce the simultaneous changes in optical and electrical behaviors.…”

“…A previous paper has shown that WO 3 ·H 2 O powder embedded in a plastic matrix could be used as the active component in the LiCoO 2 /Li electrolyte/WO 3 ·H 2 O system. With Li + intercalation the optical behavior has been well described by a Drude−Lorentz model which is often correlated to the existence of free electrons and/or to a high electronic conductivity . The role of the WO 3 ·H 2 O powder morphology was investigated on two types of compounds obtained by two different elaboration methods, − ,, the first one being constituted by microparticles (Figure a) and the second by nanoparticles (Figure b).…”

“…With Li + intercalation the optical behavior has been well described by a Drude−Lorentz model which is often correlated to the existence of free electrons and/or to a high electronic conductivity . The role of the WO 3 ·H 2 O powder morphology was investigated on two types of compounds obtained by two different elaboration methods, − ,, the first one being constituted by microparticles (Figure a) and the second by nanoparticles (Figure b). The study has evidenced a larger improvement in IR modulation properties with the increase of the particle size.…”

“…WO 3 • H 2 O is an electrochromic compound which commutes faster than WO 3 owing to the presence of water molecules which facilitates more easily cation diffusion. 5 A previous paper has shown that WO 3 • H 2 O powder embedded in a plastic matrix could be used as the active component in the LiCoO 2 /Li electrolyte/WO 3 • H 2 O system. With Li + intercalation the optical behavior has been well described by a Drude-Lorentz model which is often correlated to the existence of free electrons and/or to a high electronic conductivity.…”

Broadband Dielectric and Resistivity Spectroscopy of WO3·H2O in the Range of 103−1010 Hz: Particle Size Effect

“…So, the flexible devices could adjust to components with complex shapes, and their low weight would result in energy saving, especially for satellites. We recently reported the realization of a flexible emissivity modulator based on WO 3 ·H 2 O driven by the electrochemical insertion of lithium. − The injection of electrons comes with the insertion of small cations (typically H + or Li + ) in the compound. Hence, the variation in electron population can induce the change in optical behavior.…”