Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Fabrication of 3-Step Light Transmittance-variable Smart Windows based on λ/2 Retardation Film

λ/2 Retardation Film을 이용한 3단계 투과율 가변 스마트윈도우 제작

  • Il-Gu Kim (Smart Electronics Research Center, Korea Electronics Technology Institute) ;
  • Ho-Chang Yang (Smart Electronics Research Center, Korea Electronics Technology Institute) ;
  • Young-Min Park (Smart Electronics Research Center, Korea Electronics Technology Institute) ;
  • Yo-Han Suh (Smart Electronics Research Center, Korea Electronics Technology Institute) ;
  • Young Kyu Hong (Smart Electronics Research Center, Korea Electronics Technology Institute) ;
  • Seung Hyun Lee (Smart Electronics Research Center, Korea Electronics Technology Institute)
  • 김일구 (한국전자기술연구원 스마트전자부품연구센터) ;
  • 양호창 (한국전자기술연구원 스마트전자부품연구센터) ;
  • 박영민 (한국전자기술연구원 스마트전자부품연구센터) ;
  • 서요한 (한국전자기술연구원 스마트전자부품연구센터) ;
  • 홍영규 (한국전자기술연구원 스마트전자부품연구센터) ;
  • 이승현 (한국전자기술연구원 스마트전자부품연구센터)
  • Received : 2023.09.12
  • Accepted : 2023.09.20
  • Published : 2023.09.30
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Abstract

A fabrication of smart windows with controllable visible light transmittance in three steps by using λ/2 retardation films based on a reactive mesogen (RM) material and polarizing films is demonstrated. The phase retardation films with a Δn·d value of λ/2 (λ: wavelength) convert the direction of a traveling light to the optical axis of the film symmetrically. In this work, the retardation characteristics according to the RM thickness were evaluated and henceλ/2 phase retardation film can be fabricated. The phase retardation film with Δn·d of 276.1 nm, which is close to λ/2 (=275 nm @550 nm), was fabricated. The light transmittance of a smart window with the structure of (polarizing film)/(glass)/(alignment layer)/(λ/2 retardation film) was measured in the transmission mode, half mode and blocking mode. The evaluation results show that the transmittance of the smart window can be controlled in three steps with 35.8%, 27.8%, and 18.2% at each mode, respectively. In addition, by fabricating a smart window with a size of 15×200 mm2, the feasibility of use in various fields such as buildings and automobiles was verified.

본 연구에서는 Reactive mesogen (RM) 기반 λ/2 위상지연 필름과 편광필름을 이용하여 3단계로 투과율 가변이 가능한 스마트윈도우 제조 기술을 제안한다. λ/2 위상지연 필름은 위상차 (Γ) 값이 π (Δn·d=λ/2)이며, 위상지연 필름에 입사된 빛의 진행방향을 필름의 광축에 대칭된 각도로 변환시키는 특징이 있다. 위상지연 필름의 Δn·d 값이 λ/2에 근접할수록 변환 특성이 우수하기 때문에 본 연구에서는 복굴절 물질인 RM 두께별 retardation (Δn·d) 특성 평가를 통해 Δn·d가 λ/2(=275 nm@550 nm)에 근접한 276.1 nm의 값을 갖는 위상지연 필름을 제작하였다. 최종적으로 (편광필름)/(유리기판)/(배향막)/(λ/2 retardation film) 구조의 스마트윈도우를 제작하여 투과모드, 반투과모드, 차단모드에서의 광 투과 특성을 평가하였다. 평가결과 투과율은 각각 35.8%, 27.8%, 18.2%의 값을 나타내었으며, 이를 통해 λ/2 위상지연 필름을 이용하여 3단계로 투과율 제어 가능함을 확인하였다. 또한 150×200 mm2 크기의 스마트윈도우를 구현함으로써 건축물, 자동차 등 다양한 분야의 활용 가능성을 확인하였다.

Keywords

Acknowledgement

이 논문은 2023년도 정부(산업통상자원부)의 재원으로 한국에너지기술평가원의 지원을 받아 수행된 연구임(20202020800030, 제로에너지건축물 구현을 위한 스마트 외장재·설비융복합기술개발및성능평가체계구축, 실증)

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