Low-voltage electrochromic device for photovoltaic-powered smart windows

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.363731· OSTI ID:285547

Bechinger, C; Bullock, J N; Zhang, J; Tracy, C E; Benson, D K; Deb, S K; Branz, H M ^[1]

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1. National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)

We report the properties of an all-solid-state electrochromic (EC) device that can be switched over a useful range of optical transmissions with voltages below 1 V. This switching voltage is smaller than required by other solid-state EC devices reported to date. We attribute the lower-than-normal switching voltage to the use of a thermally evaporated MgF{sub 2} thin film as the lithium ion conducting layer. Electrochemical impedance spectroscopy studies show that high lithium ion conductivity and low interfacial barriers for lithium exchange with the adjacent electrochromic and ion storage layers make MgF{sub 2} a good choice for the ion conductor in EC devices. This reduction in switching voltage is a first step toward powering an EC device by an integrated semitransparent single-junction photovoltaic (PV) cell. In a side-by-side bench test, where the EC device is connected to a semitransparent {ital a}-SiC:H PV cell having on open circuit voltage of 0.87 V, a relative transmission change in the EC device of 40{percent} is achieved in less than 60 s. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: National Renewable Energy Laboratory
• DOE Contract Number: AC36-83CH10093
• OSTI ID: 285547
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 80; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
BLEACHING
DESIGN
ELECTROCHROMISM
IONIC CONDUCTIVITY
LITHIUM IONS
MAGNESIUM FLUORIDES
PHOTOVOLTAIC CELLS
SILICON CARBIDES
SWITCHES
THIN FILMS