Phononic thermal resistance due to a finite periodic array of nano-scatterers

• Published in: Journal of applied physics Vol. 120; no. 4
• Main Authors: Trang Nghiêm, T. T., Chapuis, Pierre-Olivier
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 28.07.2016
• Subjects: Acoustics; Applied physics; APPROXIMATIONS; Arrays; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DIFFRACTION; Energy transmission; Engineering Sciences; Filtration; FOURIER TRANSFORMATION; Fourier transforms; FREQUENCY DEPENDENCE; HOLES; KAPITZA RESISTANCE; Mechanics; Periodic variations; PHONONS; Physics; POLARIZATION; Reciprocity; ROUGHNESS; SILICON; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; Thermal conductivity; Thermal resistance; Thermics; TIME DEPENDENCE; TWO-DIMENSIONAL CALCULATIONS; Vibrations; phononics; thermal resistance; finite array; phononic crystal; acoustic phonons; thermal phonons; Kapitza resistance
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4959803

The wave property of phonons is employed to explore the thermal transport across a finite periodic array of nano-scatterers such as circular and triangular holes. As thermal phonons are generated in all directions, we study their transmission through a single array for both normal and oblique incidences, using a linear dispersionless time-dependent acoustic frame in a two-dimensional system. Roughness effects can be directly considered within the computations without relying on approximate analytical formulae. Analysis by spatio-temporal Fourier transform allows us to observe the diffraction effects and the conversion of polarization. Frequency-dependent energy transmission coefficients are computed for symmetric and asymmetric objects that are both subject to reciprocity. We demonstrate that the phononic array acts as an efficient thermal barrier by applying the theory of thermal boundary (Kapitza) resistances to arrays of smooth scattering holes in silicon for an exemplifying periodicity of 10 nm in the 5–100 K temperature range. It is observed that the associated thermal conductance has the same temperature dependence as that without phononic filtering.