Cross-plane thermal conductivity reduction of vertically uncorrelated Ge/Si quantum dot superlattices

A drastic reduction in temperature dependent cross-plane thermal conductivity κ occurs in Gequantum dotsuperlattices (QDSLs), depending on the vertical correlation between dots. Measurements show at least a twofold decrease of κ in uncorrelated dot structures as compared to structures with the same...

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Bibliographic Details
Authors: Álvarez Quintana, Jaime, Alvarez, F. Xavier|||0000-0001-6746-2144, Rodríguez-Viejo, Javier|||0000-0002-9735-263X, Jou i Mirabent, David|||0000-0003-3731-5877, Lacharmoise, Paul, Bernardi, Alessandro|||0000-0002-5529-4590, Goñi, Alejandro|||0000-0002-1193-3063, Alonso Carmona, Maria Isabel|||0000-0001-7669-5871
Format: article
Publication Date:2008
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:116048
Online Access:https://ddd.uab.cat/record/116048
https://dx.doi.org/urn:doi:10.1063/1.2957038
Access Level:Open access
Keyword:Thermal conductivity
Germanium
Superlattices
Elemental semiconductors
Quantum dots
Thin film growth
Phonons
Molecular beam epitaxy
Nanostructures
Thermoelectric devices
Description
Summary:A drastic reduction in temperature dependent cross-plane thermal conductivity κ occurs in Gequantum dotsuperlattices (QDSLs), depending on the vertical correlation between dots. Measurements show at least a twofold decrease of κ in uncorrelated dot structures as compared to structures with the same Si spacer of 20nm but good vertical dot alignment. The observed impact of disorder on the conductivity provides an alternative route to reduce the thermal conductivity of QDSLs. The results of this work have implications for the development of highly efficient thermoelectric materials and on-chip nanocooling devices.