Effects of Aperiodicity and Roughness on Coherent Heat Conduction in Superlattices
- Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Mechanical Engineering
- Virginia Tech, Blacksburg, VA (United States). Dept. of Mechanical Engineering
Coherent phonon heat conduction has recently been confirmed experimentally in superlattice structures. Such traveling coherent phonon waves in superlattices lead to a linear increase in thermal conductivity as the number of periods increases. For applications such as thermal insulation or thermoelectrics, minimization of the phonon coherent effect is desirable. In this paper, we use molecular dynamics simulations to study how to control coherent heat conduction in superlattices (SLs). It is found that either aperiodic SLs or SLs with rough interfaces can significantly disrupt coherent heat conduction when the interface densities are high. For sample thickness less than 125 nm, aperiodic SLs with perfect interfaces are found to have the lowest thermal conductivity. We use the atomic Green’s function method to examine the phonon dynamics. The impact of either aperiodicity or interface roughness is attributed to reduced transmittance. Such impact diminishes as the interface density reduces.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Solid-State Solar-Thermal Energy Conversion Center (S3TEC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0001299; FG02-09ER46577
- OSTI ID:
- 1370984
- Journal Information:
- Nanoscale and Microscale Thermophysical Engineering, Vol. 19, Issue 4; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute; ISSN 1556-7265
- Publisher:
- Taylor & FrancisCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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Related Subjects
GENERAL PHYSICS
solar (photovoltaic)
solar (thermal)
solid state lighting
phonons
thermal conductivity
thermoelectric
defects
mechanical behavior
charge transport
spin dynamics
materials and chemistry by design
optics
synthesis (novel materials)
synthesis (self-assembly)
synthesis (scalable processing)
superlattice
molecular dynamics
atomic green's function