A Flexible Quasi-Solid-State Electrochromic Device with Polymeric Electrolyte and WO3/NiO Complementary System

Jen-Yuan Wang^*, Min-Chuan Wang, Der-Jun Jan

Physics Division, Institute of Nuclear Energy Research, Taoyuan City.

DOI: 10.4236/msce.2015.37018                

Abstract

A flexible quasi-solid-state electrochromic device (ECD), assembled with a polymeric crystal composite electrolyte and tungsten oxide/nickel oxide (WO₃/NiO) complementary system, is demonstrated in this study. The polymer composite, which is composed of a UV-cured ethoxylated trimethylolpropane triacrylate (ETPTA), propylene carbonate (PC) and ferrocene (Fc), is used as the electrolyte in the flexible quasi-solid-state ECD. The optimal composition ration of this composite is at the weight ratio of 15/85 for ETPTA/PC with 1 M LiClO₄. For the cathodic electrochromic electrode, a flexible polyethylene terephthalate (PET) is used as the substrate, and indium-tin- oxide (ITO) and WO₃ are deposited sequentially on the PET by sputtering. A NiO/ITO/PET electrode prepared by sputtering is used as the anodic coloring electrode. The thickness of ITO, WO₃ and NiO film is 110, 70 and 60 nm, respectively. This flexible all-solid-state ECD fabricated with the polymeric crystal composite electrolyte shows an optical contrast of ca. 37.5% at 550 nm. The optical transmittance of the ECD at 550 nm can be reversibly modulated from 47.5% (bleached) to 10.0% (darkened), by applying potentials of 2.5 and 2.5 V, respectively.

Keywords

Electrochromism, Nickel Oxide, Polymeric Electrolyte, Tungsten Oxide

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Deb, S.K. (1969) A Novel Electrophotographic System. Applied Optics, 8, 192-195.
[2]	Niklasson, G.A. and Granqvist, C.G. (2007) Electrochromics for Smart Windows: Thin Films of Tungsten Oxide and Nickel Oxide, and Devices Based on These. Journal of Materials Chemistry, 17, 127-156. http://dx.doi.org/10.1039/B612174H
[3]	Baetens, R., Jelle, B.P. and Gustavsen, A. (2010) Properties, Requirements and Possibilities of Smart Windows for Dynamic Daylight and Solar Energy Control in Buildings: A State-of-the-Art Review. Solar Energy Materials and Solar Cells, 94, 87-105. http://dx.doi.org/10.1016/j.solmat.2009.08.021
[4]	Heuer, H.W., Wehrmann, R. and Kirchmeyer, S. (2002) Electrochromic Window Based on Conducting Poly (3,4-ethy- lenedioxythio-phene)poly(styrene sulfonate). Advanced Functional Materials, 12, 89-94. http://dx.doi.org/10.1002/1616-3028(20020201)12:2<89::AID-ADFM89>3.0.CO;2-1
[5]	Andersson, P., Nilsson, D. and Svensson, P.O. (2002) Active Matrix Displays Based on All-Organic Electrochemical Smart Pixels Printed on Paper. Ad-vanced Materials, 14, 1460-1464. http://dx.doi.org/10.1002/1521-4095(20021016)14:20<1460::AID-ADMA1460>3.0.CO;2-S
[6]	Kobayashi, N., Miura, S. and Nishimura, M. (2008) Organic Electrochromism for a New Color Electronic Paper. Solar Energy Materials and Solar Cells, 92, 136-139. http://dx.doi.org/10.1016/j.solmat.2007.02.027
[7]	Mihelcic, M., Jerman, I. and Svegl, F. (2012) Elec-trochromic Ni1?xO Pigment Coatings and Plastic Film-Based Ni1?xO/TiO2 Device with Transmissive Light Modulation. Solar Energy Materials and Solar Cells, 108, 175-187. http://dx.doi.org/10.1016/j.solmat.2012.08.012
[8]	DeLongchamp, D.M. and Hammond, P.T. (2004) High-Contrast Elec-trochromism and Controllable Dissolution of Assembled Prussian Blue/Polymer Nanocomposites. Advanced Functional Materials, 14, 224-232. http://dx.doi.org/10.1002/adfm.200304507
[9]	Granqvist, C.G. (2012) Oxide Electrochromics: An Introduction to Devices and Materials. Solar Energy Materials and Solar Cells, 99, 1-13. http://dx.doi.org/10.1016/j.solmat.2011.08.021
[10]	Granqvist, C.G. (2007) Transparent Conductors as Solar Energy Materials: A Panoramic Review. Solar Energy Materials and Solar Cells, 91, 1529-1598. http://dx.doi.org/10.1016/j.solmat.2007.04.031
[11]	Zhang, J., Wang, X.L. and Xia, X.H. (2010) Enhanced Electrochromic Performance of Macroporous WO3 Films Formed by Anodic Oxidation of DC-Sputtered Tungsten Layers. Electrochimica Acta, 55, 6953-6958. http://dx.doi.org/10.1016/j.electacta.2010.06.082
[12]	Bathe, S.R. and Patil, P.S. (2007) Electrochromic Characteristics of Fibrous Reticulated WO3 Thin Films Prepared by Pulsed Spray Pyrolysis Technique. Solar Energy Materials and Solar Cells, 91, 1097-1101. http://dx.doi.org/10.1016/j.solmat.2007.03.005
[13]	Breedon, M., Spizzirri, P. and Taylor, M. (2010) Synthesis of Nano-structured Tungsten Oxide Thin Films: A Simple, Controllable, Inexpensive, Aqueous Sol-Gel Method. Crystal Growth & Design, 10, 430-439. http://dx.doi.org/10.1021/cg9010295
[14]	Baeck, S.H., Jaramillo, T. and Stucky, G.D. (2002) Controlled Electrodeposition of Nanoparticulate Tungsten Oxide. NanoLetters, 2, 831-834. http://dx.doi.org/10.1021/nl025587p
[15]	Subrahmanyam, A. and Karuppasamy, A. (2007) Optical and Electrochromic Properties of Oxygen Sputtered Tungsten Oxide (WO3) Thin Films. Solar Energy Materials and Solar Cells, 91, 266-274. http://dx.doi.org/10.1016/j.solmat.2006.09.005
[16]	Avendano, E., Berggren, L. and Niklasson, G.A. (2006) Electrochromic Materials and Devices: Brief Survey and New Data on Optical Absorption in Tungsten Oxide and Nickel Oxide Films. Thin Solid Films, 496, 30-36. http://dx.doi.org/10.1016/j.tsf.2005.08.183
[17]	Marcilla, R., Alcaide, F. and Sardon, H. (2006) Tailor-Made Polymer Electrolytes Based upon Ionic Liquids and Their Application in All-Plastic Electrochromic Devices. Electrochemistry Communications, 8, 482-488. http://dx.doi.org/10.1016/j.elecom.2006.01.013
[18]	Lin, S.Y., Chen, Y.C. and Wang, C.M. (2012) Study of MoO3-NiO Complementary Electrochromic Devices Using a Gel Polymer Electrolyte. Solid State Ionics, 212, 81-87. http://dx.doi.org/10.1016/j.ssi.2012.02.005
[19]	Kumar, A., Otley, M.T. and Alamar, F.A. (2014) Solid-State Electrochromic Devices: Relationship of Contrast as a Function of Device Preparation Parameters. Journal of Materials Chemistry C, 2, 2510-2516. http://dx.doi.org/10.1039/c3tc32319f