Examining thermal transport through a frequency-domain representation of time-domain thermoreflectance data.
Rev Sci Instrum
; 85(12): 124903, 2014 Dec.
Article
en En
| MEDLINE
| ID: mdl-25554315
ABSTRACT
Laser-based time-domain thermoreflectance (TDTR) and frequency-domain thermoreflectance (FDTR) techniques are widely used for investigating thermal transport at micro- and nano-scales. We demonstrate that data obtained in TDTR measurements can be represented in a frequency-domain form equivalent to FDTR, i.e., in the form of a surface temperature amplitude and phase response to time-harmonic heating. Such a representation is made possible by using a large TDTR delay time window covering the entire pulse repetition interval. We demonstrate the extraction of frequency-domain data up to 1 GHz from TDTR measurements on a sapphire sample coated with a thin layer of aluminum, and show that the frequency dependencies of both the amplitude and phase responses agree well with theory. The proposed method not only allows a direct comparison of TDTR and FDTR data, but also enables measurements at high frequencies currently not accessible to FDTR. The frequency-domain representation helps uncover aspects of the measurement physics which remain obscured in a traditional TDTR measurement, such as the importance of modeling the details of the heat transport in the metal transducer film for analyzing high frequency responses.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Rev Sci Instrum
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos