Title: Thermal model for time-domain thermoreflectance experiments in a laser-flash geometry

Abstract

Time-domain thermoreflectance (TDTR) is a well-established pump–probe method for measuring thermal conductivity and interface conductance of multilayers. Interpreting signals in a TDTR experiment requires a thermal model. In standard front/front TDTR experiments, both pump and probe beams typically irradiate the surface of a multilayer. As a result, existing thermal models for interpreting thermoreflectance experiments assume that the pump and probe beams both interact with the surface layer. Here, we present a frequency-domain solution to the heat-diffusion equation of a multilayer in response to nonhomogeneous laser heating. This model allows analysis of experiments where the pump and probe beams irradiate opposite sides of a multilayer. We call such a geometry a front/back experiment to differentiate such experiments from standard TDTR experiments. As an example, we consider a 60nm amorphous Si film. We consider how signals differ in a front/front vs front/back geometry and compare thermal model predictions to experimental data.

Authors:

Peng, Wanyue; Wilson, Richard B.

• Search DOE PAGES for author "Wilson, Richard B."
• Search DOE PAGES for ORCID "0000-0002-8219-9679"

Publication Date:

Mon Apr 04 00:00:00 EDT 2022

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1860943

Grant/Contract Number:  

SC0021230

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Name: Journal of Applied Physics Journal Volume: 131 Journal Issue: 13; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics

Country of Publication:

United States

Language:

English