Electrochromic device and smart window provided with electrochromic device

Patent metadata

Field	Value
Publication number	US-10649298-B2
Application number	US-201616076996-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Feb 15, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

An electrochromic device having excellent repetitive characteristics is realized. An electrochromic device includes a first transparent electrode arranged on a first substrate, a second transparent electrode arranged on a second substrate, and a nanocrystal layer arranged on the first transparent electrode. An electrolyte is interposed between the nanocrystal layer and the second transparent electrode. The first transparent electrode, the second transparent electrode, and the nanocrystal layer do not cause an oxidation-reduction reaction when a voltage is applied to modulate a transmission spectrum, and do not include an electrode that causes modulation of a transmission spectrum by an oxidation-reduction reaction when a voltage is applied.

First claim

The invention claimed is:

1. An electrochromic device that modulates a transmission spectrum by applying a voltage, comprising:
a first transparent electrode arranged on a first substrate;
a second transparent electrode arranged on a second substrate; and
a nanocrystal layer arranged on the first transparent electrode, wherein
the nanocrystal layer and the second transparent electrode are arranged to face each other,
an electrolyte is interposed between the nanocrystal layer and the second transparent electrode, and
the first transparent electrode, the second transparent electrode, and the nanocrystal layer do not cause an oxidation-reduction reaction when a voltage is applied to modulate a transmission spectrum, and do not include an electrode that causes modulation of a transmission spectrum by an oxidation-reduction reaction when a voltage is applied.

2. The electrochromic device according to claim 1 , further comprising
a spacer for keeping a distance in between the nanocrystal layer and the second transparent electrode constant.

3. The electrochromic device according to claim 1 , wherein
the nanocrystal layer contains tin-doped indium oxide (ITO) nanocrystals.

4. The electrochromic device according to claim 1 , further comprising
an overcurrent protection circuit that, in a case where it is detected that a current exceeding a predetermined threshold flows between the first transparent electrode and the second transparent electrode, disconnects a connection between the first transparent electrode and the second transparent electrode so that no current flows between the first transparent electrode and the second transparent electrode, or switches a connection destination of a power supply to a circuit different from a circuit connecting the first transparent electrode and the second transparent electrode.

5. The electrochromic device according to claim 4 , wherein
the predetermined threshold value varies depending on energization time for the electrochromic device.

6. The electrochromic device according to claim 1 , further comprising
an overcurrent protection circuit that, in a case where a charge amount charged in the electrochromic device exceeds a predetermined charge amount threshold value, stops applying a voltage between the first transparent electrode and the second transparent electrode of the electrochromic device, or lowers an absolute value of a voltage to be applied.

7. The electrochromic device according to claim 1 , wherein
the first transparent electrode is divided into a plurality of sub-electrodes corresponding to a plurality of regions.

8. The electrochromic device according to claim 7 , wherein
the second transparent electrode is divided into a plurality of sub-electrodes corresponding to a plurality of regions.

9. A smart window comprising
the electrochromic device according to claim 1 .

Assignees

• Sharp Kk

Inventors

• Satoh Eiji
• Ito Nobuyuki

Classifications

• G02F2201/50

  Protective arrangements · CPC title

• E06B3/66304

  Discrete spacing elements, e.g. for evacuated glazing units · CPC title

• G02F1/1533

  structural features not otherwise provided for · CPC title

• G02F2001/164

  the electrolyte is made of polymers · CPC title

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title