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Title: Investigation of Thermal Properties of β-Ga 2 O 3 Nanomembranes on Diamond Heterostructure Using Raman Thermometry

Theβ-Ga2O3nanomembrane (NM)/diamond heterostructure is one of the promising ultra-wide bandgap heterostructures that offers numerous complementary advantages from both materials. In this work, we have investigated the thermal properties of theβ-Ga2O3NM/diamond heterostructure with three different thicknesses ofβ-Ga2O3nanomembranes (NMs), namely 100 nm, 1000 nm, and 4000 nm thickβ-Ga2O3NMs using Raman thermometry. The thermal property—temperature relationships of theseβ-Ga2O3NM/diamond heterostructures, such as thermal conductivity and interfacial thermal boundary conductance were determined under different temperature conditions (from 100 K to 500 K with a 40 K interval). The result provides benchmark knowledge about the thermal conductivity ofβ-Ga2O3NMs over a wide temperature range for the design of novelβ-Ga2O3-based power electronics and optoelectronics.

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ECS Journal of Solid State Science and Technology
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Article No. 055007
The Electrochemical Society
Sponsoring Org:
National Science Foundation
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  1. Abstract

    In this work, we report a simplified method to measure thermal conductivity from the typical Raman thermometry method by employing a much simpler dispersion relationship equation and the Debye function, instead of solving the heat equation. Unlike the typical Raman thermometry method, our new method only requires monitoring of the temperature-dependent Raman mode shifting without considering laser power-dependent Raman mode shifting. Thus, this new calculation method offers a simpler way to calculate the thermal conductivity of materials with great precision. As a model system, theβ-Ga2O3nanomembrane (NM) on a diamond substrate was prepared to measure thermal conductivity ofβ-Ga2O3NMs at different thicknesses (100 nm, 1000 nm, and 4000 nm). Furthermore, the phonon penetration depth was investigated to understand how deep phonons can be dispersed in the sample so as to guide the dimensional design parameter of the device from the thermal management perspective.

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