Heat transport through propagon-phonon interaction in epitaxial amorphous-crystalline multilayers

Abstract

Managing heat dissipation is a necessity for nanoscale electronic devices with high-density interfaces, but despite considerable effort, it has been difficult to establish the phonon transport physics at the interface due to a “complex” interface layer. In contrast, the amorphous/epitaxial interface is expected to have almost no “complex” interface layer due to the lack of lattice mismatch strain and less associated defects. Here, we experimentally observe the extremely-small interface thermal resistance per unit area at the interface of the amorphous-germanium sulfide/epitaxial-lead telluride superlattice (~0.8 ± 4.0 × 10‒9 m2KW−1). Ab initio lattice dynamics calculations demonstrate that high phonon transmission through this interface can be predicted, like electron transport physics, from large vibron-phonon density-of-states overlapping and phonon group velocity similarity between propagon in amorphous layer and “conventional” phonon in crystal. This indicates that controlling phonon (or vibron) density-of-states and phonon group velocity similarity can be a comprehensive guideline to manage heat conduction in nanoscale systems.

Substrate-dependence of monolayer MoS2 thermal conductivity and thermal boundary conductance

“…3. The overlap of VDOS between two materials has been tied to the transmission of phonons at an interface in previous TBC studies [20,[58][59][60][61][62] and can be used here to understand the interaction between the MoS 2 and its substrate, with the presumption that a smaller overlap of VDOS with MoS 2 will result in a smaller TC degradation in MoS 2 .…”

Nanocalorimetry using microscopic optical wireless integrated circuits

“…Future designs will integrate complementary metal–oxide–semiconductor circuitry to reduce the power consumption and explore intensity independent measurement schemes. Potential applications include everything from rapid probing the heat capacity of microcrystals too small for traditional methods ( 38 ) to local thermal measurements of biological tissue in vivo ( 39 ).…”

Tunable Thermal Switch via Order–Order Transition in Liquid Crystalline Block Copolymer

“…The specific heat capacity was measured using differential scanning calorimetry (Supporting Information S2). The out-of-plane κ was measured using homemade 2ω apparatus, where κ is acquired on the basis of one-dimensional heat conduction model. − Au transducer films with a thickness of ∼200 nm were deposited on the surfaces of BC films. Joule heating of Au film was caused by flowing a sinusoidal heat current with a frequency of 1–10 kHz and a magnitude of ∼800 mA.…”

“…The laser with a power of 50 mW and a wavelength of 532 nm was irradiated on the surface of Au film, and then the thermoreflectance signal was detected with Si photodiodes. The details are described in our previous studies. − When increasing T too much, the surface of Au film is roughened, which makes it difficult to detect thermoreflectance signal. In this study, κ measurements were performed within the T range that v-BC can reversibly undergo the order–order transition without roughening of the surface of Au film.…”