| 项目编号: | 1351881
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| 项目名称: | CAREER: Ultrafast Phonon Dynamics in Complex Nanostructures: Systematic Investigation with Ultrafast Phonon Spectroscopy and Femtosecond Thermal Reflectance Technique |
| 作者: | Yaguo Wang
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| 承担单位: | University of Texas at Austin
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| 批准年: | 2013
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| 开始日期: | 2014-06-01
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| 结束日期: | 2019-05-31
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| 资助金额: | USD402400
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | ultrafast phonon spectroscopy
; phonon
; specific phonon mode
; microscopic phonon property
; ultrafast phonon dynamics
; ultrafast optics
; individual phonon
; phonon transport
; phonon dynamics
; phonon lifetime
; individual phonon behavior
; different nanostructure
; complex nanostructure
; femtosecond thermal reflectance techniquephonon
; time domain thermal reflectance technique
; systematic investigation
; femtosecond time domain thermal reflectance technique
; effect
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| 英文摘要: | CBET-1351881
PI: Yaguo Wang, University of Texas at Austin
CAREER: Ultrafast Phonon Dynamics in Complex Nanostructures: Systematic Investigation with Ultrafast Phonon Spectroscopy and Femtosecond Thermal Reflectance Technique
Phonons are quantized lattice vibrations and the major heat carriers in many crystalline materials. Our scientific understanding of phonons lags behind that of electrons and photons, mainly because of the difficulties in measuring and manipulating individual phonon. In bulk materials, the phonon transport is purely diffusive and governed by Fourier's Law. In nanostructures, phonons can travel ballistically, scatter at boundaries, interfaces and nanoparticles, and can be localized by quantum confinement effects. When different nanostructures are integrated together, phonon dynamics becomes exceptionally complicated. This research will investigate individual phonon behavior in complex nanostructures with ultrafast phonon spectroscopy and femtosecond time domain thermal reflectance technique. The effect of different nanostructures on specific phonon modes will be examined in detail through a systematic introduction of boundaries, interfaces, nanoparticles, and quantum wells into the material. Phonon lifetime and group velocity will be characterized for specific phonon modes with the ultrafast phonon spectroscopy, and the effect on macroscopic thermal conductivity will be measured by time domain thermal reflectance technique. Quantitative information will be provided about the effects resulting from the degree of lattice-mismatch, superlattice period, nanoparticle size, type and concentration, and the interplay of these mechanisms. The results will be used to validate the predictions from numerical and theoretical studies and bridge the gap between macroscopic thermal property measurements and microscopic phonon properties.
This research will address the fundamental heat transport problems encountered by researchers in a wide variety of disciplines: thermoelectrics, quantum cascade lasers, infrared detectors, and nanoelectronics. The new discoveries obtained from this study will be integrated into both graduate and undergraduate courses. This project will prepare next-generation leaders in thermal sciences, ultrafast optics, material science and physics. Outreach activities will include demonstrating research findings in pre-college programs focused on K-12 students, and providing research opportunities to undergraduate women mentored by graduate women. This project will also enhance diversity at University of Texas at Austin by actively recruiting graduate students from under-represented populations, such as women and minorities. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96655
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Yaguo Wang. CAREER: Ultrafast Phonon Dynamics in Complex Nanostructures: Systematic Investigation with Ultrafast Phonon Spectroscopy and Femtosecond Thermal Reflectance Technique. 2013-01-01.
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