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Photonic Approaches to Controlling Infrared Emissivity: Fundamental Strategies and Novel Cooling Applications
Photonic Approaches to Controlling Infrared Emissivity: Fundamental Strategies and Novel Cooling Applications
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202104808
- ISBN
- 9798290924106
- DDC
- 621.3
- 서명/저자
- Photonic Approaches to Controlling Infrared Emissivity: Fundamental Strategies and Novel Cooling Applications
- 발행사항
- [Sl] : University of California, Los Angeles, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 184 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-02, Section: B.
- 주기사항
- Advisor: Raman, Aaswath.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2025.
- 초록/해제
- 요약Thermal radiation is ubiquitous, and controlling it at the material level is central to various applications, including energy harvesting, imaging, sensing, and thermal management. Additionally, amid rising global temperatures, radiative heat transfer has become crucial for active and passive cooling strategies.Controlling thermal emission spectrally and directionally significantly advances thermal management technologies. Epsilon-near-zero (ENZ) films are widely studied, but they primarily control the p‑polarization only, limiting the magnitude of heat transfer. This study introduces effective mu‑near‑zero (MNZ) metamaterials to enable control over s‑polarized thermal emission. We theoretically explore MNZ behavior and propose a thin‑film stack of doped semiconductor films with tunable plasmon frequencies to experimentally realize simultaneous epsilon‑near‑zero and mu‑near‑zero responses. Using numerical optimization, we design a stack that achieves directional and spectral control over both polarizations, achieving a peak unpolarized emissivity of 0.81.Parallel to thermal emission control is the need for effective outdoor cooling to combat climate change. Active radiant cooling is promising but typically requires many actively cooled surfaces, complicating designs and reducing internal visibility. We demonstrate thermal comfort in an outdoor structure that lightly employs radiant cooling by utilizing visibly transparent, low‑emissivity, infrared‑reflective surfaces. We develop an analytical model linking mean radiant temperature to cold and reflective surfaces and experimentally validate it, including a thermal comfort survey. This approach achieves practical thermal comfort in extreme heat conditions with fewer actively cooled surfaces.Additionally, passive techniques are explored through a novel material, which provides cooler‑than‑ordinary shade by employing passive daytime radiative cooling. A thin‑film germanium layer on porous polyethylene blocks sunlight while remaining infrared‑transparent, allowing human body heat to transmit and escape through the atmospheric transparency window. We experimentally validate cooling, showing a 1°C reduction in temperature compared to a control.Finally, thermal radiation is critical for space‑based photovoltaics where it is the sole heat dissipation mechanism. Since cooling is defined and limited by Planck's law, we propose reducing heat generation as a means to lower the operating temperature and increase electrical output. A coupled detailed‑balance and thermal model validates that limiting photovoltaic conversion to shorter wavelengths increases electrical output.
- 일반주제명
- Electrical engineering
- 일반주제명
- Materials science
- 일반주제명
- Applied physics
- 키워드
- Radiant cooling
- 키워드
- Thermal comfort
- 기타저자
- University of California, Los Angeles Materials Science and Engineering 0328
- 기본자료저록
- Dissertations Abstracts International. 87-02B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202104808
■006m o d
■007cr#unu||||||||
■020 ▼a9798290924106
■035 ▼a(MiAaPQ)AAI32166182
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a621.3
■1001 ▼aAbraham, David Esam Joseph.
■24510▼aPhotonic Approaches to Controlling Infrared Emissivity: Fundamental Strategies and Novel Cooling Applications
■260 ▼a[Sl]▼bUniversity of California, Los Angeles▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a184 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-02, Section: B.
■500 ▼aAdvisor: Raman, Aaswath.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2025.
■520 ▼aThermal radiation is ubiquitous, and controlling it at the material level is central to various applications, including energy harvesting, imaging, sensing, and thermal management. Additionally, amid rising global temperatures, radiative heat transfer has become crucial for active and passive cooling strategies.Controlling thermal emission spectrally and directionally significantly advances thermal management technologies. Epsilon-near-zero (ENZ) films are widely studied, but they primarily control the p‑polarization only, limiting the magnitude of heat transfer. This study introduces effective mu‑near‑zero (MNZ) metamaterials to enable control over s‑polarized thermal emission. We theoretically explore MNZ behavior and propose a thin‑film stack of doped semiconductor films with tunable plasmon frequencies to experimentally realize simultaneous epsilon‑near‑zero and mu‑near‑zero responses. Using numerical optimization, we design a stack that achieves directional and spectral control over both polarizations, achieving a peak unpolarized emissivity of 0.81.Parallel to thermal emission control is the need for effective outdoor cooling to combat climate change. Active radiant cooling is promising but typically requires many actively cooled surfaces, complicating designs and reducing internal visibility. We demonstrate thermal comfort in an outdoor structure that lightly employs radiant cooling by utilizing visibly transparent, low‑emissivity, infrared‑reflective surfaces. We develop an analytical model linking mean radiant temperature to cold and reflective surfaces and experimentally validate it, including a thermal comfort survey. This approach achieves practical thermal comfort in extreme heat conditions with fewer actively cooled surfaces.Additionally, passive techniques are explored through a novel material, which provides cooler‑than‑ordinary shade by employing passive daytime radiative cooling. A thin‑film germanium layer on porous polyethylene blocks sunlight while remaining infrared‑transparent, allowing human body heat to transmit and escape through the atmospheric transparency window. We experimentally validate cooling, showing a 1°C reduction in temperature compared to a control.Finally, thermal radiation is critical for space‑based photovoltaics where it is the sole heat dissipation mechanism. Since cooling is defined and limited by Planck's law, we propose reducing heat generation as a means to lower the operating temperature and increase electrical output. A coupled detailed‑balance and thermal model validates that limiting photovoltaic conversion to shorter wavelengths increases electrical output.
■590 ▼aSchool code: 0031.
■650 4▼aElectrical engineering
■650 4▼aMaterials science
■650 4▼aApplied physics
■653 ▼aPassive daytime radiative cooling
■653 ▼aRadiant cooling
■653 ▼aSpace photovoltaics
■653 ▼aThermal comfort
■653 ▼aThermal radiation
■653 ▼aEpsilon-near-zero
■690 ▼a0794
■690 ▼a0544
■690 ▼a0215
■71020▼aUniversity of California, Los Angeles▼bMaterials Science and Engineering 0328.
■7730 ▼tDissertations Abstracts International▼g87-02B.
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17358905▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
