Infrared Phonon Thermoreflectance in Polar Dielectrics

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Zare, Saman, Hutchins, William D., Hirt, Daniel, Golightly, Elizabeth, Hopkins, Patrick E.
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866910189896073216
author Zare, Saman
Hutchins, William D.
Hirt, Daniel
Golightly, Elizabeth
Hopkins, Patrick E.
author_facet Zare, Saman
Hutchins, William D.
Hirt, Daniel
Golightly, Elizabeth
Hopkins, Patrick E.
contents In this work, we investigate dielectric materials for thermoreflectance-based thermal sensing by extracting key optical parameters using temperature-dependent spectroscopic ellipsometry in the mid-infrared regime. Leveraging optical phonon resonances, we demonstrate that the thermoreflectance coefficients in polar dielectrics rival, and in some cases exceed by an order of magnitude, those observed in commonly used metals that are typically used as temperature transducers in thermoreflectance measurements. We introduce a transducer figure of merit (FOM) that combines pump absorption and probe reflectance modulation at different wavelengths, serving as a design-oriented screening metric for comparing thermoreflectance transducer performance across materials and spectral regions. Our results show that polar materials can exhibit performance up to eight times greater than that of metal transducers. To demonstrate practical capability, we perform transient thermoreflectance measurements on a 100 nm thermally grown SiO2 film on silicon. These results position dielectric materials as compelling candidates for next-generation thermal metrology, broadening the design space for optical thermometry, with strong implications for high-resolution thermal mapping and characterization of layered device structures based on phonon probing.
format Preprint
id arxiv_https___arxiv_org_abs_2504_05675
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Infrared Phonon Thermoreflectance in Polar Dielectrics
Zare, Saman
Hutchins, William D.
Hirt, Daniel
Golightly, Elizabeth
Hopkins, Patrick E.
Optics
Materials Science
In this work, we investigate dielectric materials for thermoreflectance-based thermal sensing by extracting key optical parameters using temperature-dependent spectroscopic ellipsometry in the mid-infrared regime. Leveraging optical phonon resonances, we demonstrate that the thermoreflectance coefficients in polar dielectrics rival, and in some cases exceed by an order of magnitude, those observed in commonly used metals that are typically used as temperature transducers in thermoreflectance measurements. We introduce a transducer figure of merit (FOM) that combines pump absorption and probe reflectance modulation at different wavelengths, serving as a design-oriented screening metric for comparing thermoreflectance transducer performance across materials and spectral regions. Our results show that polar materials can exhibit performance up to eight times greater than that of metal transducers. To demonstrate practical capability, we perform transient thermoreflectance measurements on a 100 nm thermally grown SiO2 film on silicon. These results position dielectric materials as compelling candidates for next-generation thermal metrology, broadening the design space for optical thermometry, with strong implications for high-resolution thermal mapping and characterization of layered device structures based on phonon probing.
title Infrared Phonon Thermoreflectance in Polar Dielectrics
topic Optics
Materials Science
url https://arxiv.org/abs/2504.05675