Electrochromic smart devices

A. Azens and C. G. Granqvist [2003] Electrochromic Smart Windows Energy Efficiency and Device Aspects, J. Solid State Electrochem. 7, 64-68. 

In general, the term electrochromism is used to describe the change in light absorption as a result of an electrochemical reaction. Recent interest in electrochromism stems from its potential applications in numerous devices, such as flat screen displays, antidazzle mirrors, smart windows, and others. 

Figure 33.1a illustrates the idea of the smart window. In this device a layer of electrochromic material and a layer of a transparent ion-conducting electrolyte are sandwiched between two optically transparent electrodes (OTEs). Indium-doped tin oxide on glass is used most commonly as the OTE. This material has very low... 

A general schematic for a smart window is shown in Figure 13.10. This device is, quite literally, two chemically modified electrodes sandwiched together. In this case, the films coating the electrode surfaces are electrochromic materials. A polymer electrolyte, analogous to that used in the fuel cell discussed earlier, is sandwiched between these two electrochromic material-coated electrodes. In a recent example of this concept by Habib and Maheswari of General Motors Research Laboratories [94], the cathodic electrochromic material was a tungsten oxide and the cathodic electrochromic material was the material Prussian blue, discussed in Section II of this chapter. It seems likely that electrochromic cells will soon find their way into the commercial marketplace. 

Since mesoporous materials contain pores from 2 nm upwards, these materials are not restricted to the catalysis of small molecules only, as is the case for zeolites. Therefore, mesoporous materials have great potential in catalytic/separation technology applications in the fine chemical and pharmaceutical industries. The first mesoporous materials were pure silicates and aluminosilicates. More recently, the addition of key metallic or molecular species into or onto the siliceous mesoporous framework, and the synthesis of various other mesoporous transition metal oxide materials, has extended their applications to very diverse areas of technology. Potential uses for mesoporous smart materials in sensors, solar cells, nanoelectrodes, optical devices, batteries, fuel cells and electrochromic devices, amongst other applications, have been suggested in the literature.11 51... 

The considerable changes in the optical absorption of CPs during the dopingundoping process are at the basis of many proposals for electrochromical devices, such as smart windows, whose light transmission can be electrically controlled, and various display devices. Due to the drastic change that appears in their visible spectrum, PTh [122-124] and PAni [125] are... 

Figure 10 Electrochromic device, or smart window using a conducting polymer as the active material.

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