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DOE OSTI · 3733651

Modulation of thermal conductivity of iron-doped ß-Ga2O3 by helium-ion irradiation

Kulathuvayal, Arjun S. [Utah State University]·Shiau, Ching-heng [Boise State University]·Su, Yanqing [Utah State University]·Chen, Di [University of Nevada]·Yang, Ge [North Carolina State University]·Sun, Cheng [Clemson University]·Hua, Zilong [Idaho National Laboratory] (ORCID:0000000229423344)
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Abstract

This study examines the impact of helium-ion irradiation on the thermal conductivity of ß-Ga2O3. A laser-based spatial domain thermoreflectance technique is used to investigate thermal conductivity map for both un-irradiated and irradiated ß-Ga2O3, which are then validated against simulation results derived from density functional theory-based phonon transport simulations. Since helium bubble evolution was ob- served at the nanoscale using transmission electron microscopy, the simulation study was carried out on eight distinct helium-induced sites in ß-Ga2O3. Our findings indicate a reduction in thermal conductivity for the irradiated samples. Experimental results show a significant reduction in thermal conductivity in irradiated samples, with de- creases of approximately 25% along the [100] direction and 40% along [001] directions. Phonon transport simulations closely replicate these findings, particularly when helium occupying interstitial sites, predicting reductions of ˜53% along [100] and ˜50% along [001] directions. This work underscores the role of irradiation-induced microstructural changes in the heat transport properties of ß-Ga2O3 which is crucial for its application in sensor devices in extreme environments.

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Kulathuvayal, Arjun S. [Utah State University], Shiau, Ching-heng [Boise State University], Su, Yanqing [Utah State University], Chen, Di [University of Nevada], Yang, Ge [North Carolina State University], Sun, Cheng [Clemson University], Hua, Zilong [Idaho National Laboratory] (ORCID:0000000229423344). 2025-08-14. Modulation of thermal conductivity of iron-doped ß-Ga2O3 by helium-ion irradiation. https://doi.org/10.1016/j.jallcom.2025.182949

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