2017/10/25 by John T. Gaskins, George N. Kotsonis, Gaskins, John T. +28
Engineering · Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #GaN-based semiconductor devices and materials #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Thermal Radiation and Cooling Technologies #Thermal properties of materials
paper · pdf · doi:10.48550/arxiv.1710.09525
openalex publication_date 2017/10/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present experimental measurements of the thermal boundary conductance\n(TBC) from 77 - 500 K across isolated heteroepitaxially grown ZnO films on\nGaN substrates. These data provide an assessment of the assumptions that drive\nthe phonon gas model-based diffuse mismatch models (DMM) and atomistic Green's\nfunction (AGF) formalisms for predicting TBC. Our measurements, when compared\nto previous experimental data, suggest that the TBC can be influenced by long\nwavelength, zone center modes in a material on one side of the interface as\nopposed to the "vibrational mismatch" concept assumed in the DMM; this\ndisagreement is pronounced at high temperatures. At room temperature, we\nmeasure the ZnO/GaN TBC as 490 lbrack +150, -110 rbrack MW m-2 K-1.\nThe disagreement among the DMM and AGF and the experimental data these elevated\ntemperatures suggests a non-negligible contribution from additional modes\ncontributing to TBC that not accounted for in the fundamental assumptions of\nthese harmonic formalisms, such as inelastic scattering. Given the high quality\nof these ZnO/GaN interface, these results provide an invaluable critical and\nquantitive assessment of the accuracy of assumptions in the current state of\nthe art of computational approaches for predicting the phonon TBC across\ninterfaces.\n