Phonon transport governed by intrinsic scattering in short-period AlN/GaN superlattices
Journal Article
·
· Physical Review. B
- Vanderbilt Univ., Nashville, TN (United States)
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Here we employ density functional theory based phonon transport methods to provide a rigorous understanding of the nature of thermal transport in coherent short-period AlN/GaN superlattices (SLs), with period lengths up to three unit cells of each, and compare these with properties of their bulk constituents. Increasing the period length leads to phonon band folding with frequency gaps and thus smaller phonon velocities and more phonon scattering than in bulk, both of which reduce lattice thermal conductivity (κ). Contrary to expectations, we find that velocity variations among larger-period AlN/GaN SLs play only a minor role in cross-plane κ reductions, while variations in intrinsic phonon scattering are strongly correlated with their transport behaviors. This work provides insights into the microscopic behaviors of technologically relevant nanostructured materials, which are likely applicable to a wider range of SL systems and other nanostructures.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- AC02-05CH11231; AC05-00OR22725
- OSTI ID:
- 2333809
- Alternate ID(s):
- OSTI ID: 2473749
- Journal Information:
- Physical Review. B, Journal Name: Physical Review. B Journal Issue: 10 Vol. 109; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Raman analysis of phonon modes in a short period AlN/GaN superlattice
Phonons and free carriers in a strained hexagonal GaN-AlN superlattice measured by infrared ellipsometry and Raman spectroscopy
Phonon thermal conductance across GaN-AlN interfaces from first principles
Journal Article
·
Fri Feb 02 19:00:00 EST 2018
· Superlattices and Microstructures
·
OSTI ID:1439812
Phonons and free carriers in a strained hexagonal GaN-AlN superlattice measured by infrared ellipsometry and Raman spectroscopy
Conference
·
Sat Jul 01 00:00:00 EDT 2000
·
OSTI ID:20104609
Phonon thermal conductance across GaN-AlN interfaces from first principles
Journal Article
·
Thu Jan 31 19:00:00 EST 2019
· Physical Review B
·
OSTI ID:1494888