Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Characteristics of an electrochromic ECD (electro-chromic device) film in applications for smart windows with a 4-layer structure, a thickness of 0.5 mm

0.5 mm 이내의 두께를 갖는 4층 구조의 스마트 윈도우에 적용되는 전기변색 ECD(electro-chromic device) 필름 제조 및 특성

  • Nam Il Kim (Department of Chemical Engineering, Hannam University) ;
  • Geug Tae Kim (Department of Chemical Engineering, Hannam University)
  • 김남일 (한남대학교 공과대학 화학공학과) ;
  • 김극태 (한남대학교 공과대학 화학공학과)
  • Received : 2024.01.23
  • Accepted : 2024.02.13
  • Published : 2024.02.29
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Abstract

Using electrochromic devices (ECD), smart window films that can change the colors from tinted state into transparent state by applying an external voltage were manufactured. Polyethylene terephthalate (PET) film was used as a substrate instead of conventional glass, and ECD modules having a total thickness of about 50 ㎛ were manufactured by sequentially introducing an ITO/Ag/ITO electrode layer, a WO3/TIC2 organic discoloration layer, and a Nafion fluorine electrolyte layer. Through a series of sputtering, bar coating, and thermal compression processes, a large scale smart window with a horizontal and vertical length of more than 80 mm was manufactured. When DC 3.5 V was applied, the transmittance decreased from 54 % to 24 % and moreover the color change could be confirmed even with the naked eye. Reversible color change capability at low external voltage implies that external sunlight can be selectively blocked which is effective in terms of energy saving.

전기변색(electrochromic devices, ECD) 방식을 이용하여 외부 전압 인가에 의해 착색된 상태에서 투명한 상태로 색 변화를 일으킬 수 있는 필름 형태의 스마트 윈도우를 제조하였다. 기존 유리 대신 투명 PET 필름을 기재로 사용하였고 ITO/Ag/ITO 전극층, WO3/TIC2 유기변색층, Nafion 전해질층을 차례로 도입한 이후 합지 공정을 통하여 총 두께가 50 ㎛ 정도인 다층 박막 ECD 모듈을 제조하였다. 길이가 80 mm 이상인 대면적의 ECD 모듈을 제조하기 위하여 스퍼터링, 바코팅, 열압축 공정을 최적화하였다. 보통 상태에서 54 % 수준의 투과율을 보였으나 DC 3.5 V의 전압을 인가했을 때 24 %까지 떨어졌으며 색 변화는 육안으로도 확인할 수 있었다. 가역적인 색 변화에 의해 외부 태양광을 선택적으로 차단할 수 있으며 냉난방에 필요한 에너지 저감 측면에서 효과적일 것으로 예상된다.

Keywords

Acknowledgement

본 연구는 "2021년도 첨단소재산업 기술지원사업" 연구 사업(대전테크노파크)으로 수행되었으며, 이에 감사드립니다(과제명: 0.5 mm 이내 4층구조를 갖는 스마트 윈도우에 적용되는 전기변색 ECD(electro-chromic device) film형 모듈 시제품 개발). 연구결과물의 학술지 게재를 허락하신 (주)알에스엠큐브 김극태 대표와 제작장비 지원하신 (주)유니플라텍 강석환 대표에게 감사드립니다.

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