Infrared switching electroemissive devices based on highly conducting polymers

Different types of electrochromic devices for thermal emittance modulation were developed in the spectral region from mid-to far-infrared ͑2-40 m͒. In all devices polycrystalline and amorphous tungsten oxide have been used as electrochromic and ion storage layer, respectively. Two types of all-solid-state devices were designed, one with a metal grid for the top and bottom electrode deposited on a highly emissive glass substrate, and another with a top metal grid electrode and a highly reflecting bottom metal electrode layer. Tantalum oxide is used as an ion conductor in both device types. The third device type consists of a polymeric ion conductor. All solid-state constituent layers were grown by either reactive or nonreactive dc or rf magnetron sputtering in a high vacuum environment. Modulation of the emittance is accomplished by reversible insertion of Li ions into polycrystalline WO 3 by applying and switching a small voltage across the structure. Spectrally dependent measured reflectance modulation of the device has been used to determine the device emissivity modulation with respect to the blackbody emissivity spectra at 300 K. Best device performance was found in both solid-state devices showing an emissivity modulation of about 20%.

show abstract

“…Here the emittance modulation is related to the reflectance modulation of the device. Topart et al 13 and Trimble et al…”

Section: Introductionmentioning

confidence: 98%

Infrared switching electrochromic devices based on tungsten oxide

Franke¹,

Trimble²,

Hale³

et al. 2000

Journal of Applied Physics

111

View full text Add to dashboard Cite

show abstract

“…Increasingly, attention has been focused towards optical changes at longer wavelengths, extending from the near infrared (NIR) through the microwave regions of the spectrum. [5][6][7] Of the available electrochromic materials, conjugated conducting polymers have become widely researched electrochromic materials because of their fast switching speeds, improved processability, and color tunability through structural modification. [8][9][10][11][12] Recently, our group has produced a series of alkyland alkoxy-substituted poly(3,4-propylenedioxythiophene)s (PProDOTs) that are soluble in common organic solvents and therefore easily processable by spin-coating or spray-casting.…”

Section: Introductionmentioning

confidence: 99%

A Poly(3,4‐alkylenedioxythiophene) Electrochromic Variable Optical Attenuator with Near‐Infrared Reflectivity Tuned Independently of the Visible Region

Dyer

Grenier

Reynolds

2007

Adv Funct Materials

121

View full text Add to dashboard Cite

Disubstituted poly(3,4‐propylenedioxythiophene)s (PProDOTs) exhibit large electrochromic contrasts in the near infrared (NIR) while showing essentially no color change in the visible region when incorporated into a reflective device platform. The source of this is attributed to a conductive front that propagates through the insulating polymer film, extending from the polymer/electrode interface to the top of the polymer film. A utility of the large contrasts seen in the NIR region is demonstrated with application of the device as an electrochromic variable optical attenuator modulating fiber‐optic signals for optical telecommunications. With bis(ethylhexyloxy)‐substituted PProDOT as the active electrochromic polymer in the device, an optical attenuation of 11 dB at the telecommunications wavelengths of 1.31 and 1.55 μm is achieved with only a 0.1–0.2 dB optical loss in the bleached state. Other favorable properties include optical memory in the absorbing state, switching speeds of under 1 s, a low operating voltage of ±1.2 V, and an improved processability that allows spray‐casting from organic solvents.

show abstract

“…The latter electrochromic materials were radio frequency sputtered on Au substrate at ambient temperature in 6 Pa of chamber pressure. In comparison, for long wavelength band (LW,(8)(9)(10)(11)(12), the contrast in reflectance did not exceed 30%. The origins of the various electrochromic behaviours are correlated to the film structure, morphology and composition, indicating better properties for porous, nonstoichiometric films.…”

mentioning

confidence: 81%

“…Since then, a few applications including helmet visors or glasses have been reported whereas the most challenging one remains the development of smart windows for use in building and automobile [2,4]. Until recently, most of the applications were turned towards the visible region whereas the IR domain is much less addressed [5][6][7][8][9][10]. In the defence area, the preparation of coatings for vehicles and persons, which would be able to blend into their surrounding and, therefore, become invisible to an infrared camera, is highly desirable [11].…”

Section: Introductionmentioning

confidence: 99%

Electrochromic materials from the visible to the infrared region: an example WO3

Rougier

Sauvet

Sauques

2008

Ionics

View full text Add to dashboard Cite

Herein, the example of the most typical electrochromic material, namely WO 3 , is used to illustrate the potential of electrochromic materials for controlling infrared reflectance and hence, emissivity. Playing with various growth parameters, contrast in reflectance between the inserted H x WO 3 and deinserted WO 3 states as high as 73% in mid-wavelength band (MW, 3-5 μm) was achieved for 320 nm WO 3 films. The latter electrochromic materials were radio frequency sputtered on Au substrate at ambient temperature in 6 Pa of chamber pressure. In comparison, for long wavelength band (LW,(8)(9)(10)(11)(12), the contrast in reflectance did not exceed 30%. The origins of the various electrochromic behaviours are correlated to the film structure, morphology and composition, indicating better properties for porous, nonstoichiometric films.

show abstract

Infrared switching electroemissive devices based on highly conducting polymers

Cited by 94 publications

References 13 publications

Infrared switching electrochromic devices based on tungsten oxide

Infrared switching electrochromic devices based on tungsten oxide

A Poly(3,4‐alkylenedioxythiophene) Electrochromic Variable Optical Attenuator with Near‐Infrared Reflectivity Tuned Independently of the Visible Region

Electrochromic materials from the visible to the infrared region: an example WO3

Contact Info

Product

Resources

About