Thermal conduction in lattice–matched superlattices of InGaAs/InAlAs

Journal Article · Mon Aug 04 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4892575· OSTI ID:22314699

Sood, Aditya ^[1]; Rowlette, Jeremy A. ^[2]; Caneau, Catherine G. ^[3]; Bozorg-Grayeli, Elah; Asheghi, Mehdi

---

1. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)
2. Daylight Solutions, San Diego, California 92128 (United States)
3. Corning Incorporated, Corning, New York 14831 (United States)

Understanding the relative importance of interface scattering and phonon-phonon interactions on thermal transport in superlattices (SLs) is essential for the simulation of practical devices, such as quantum cascade lasers (QCLs). While several studies have looked at the dependence of the thermal conductivity of SLs on period thickness, few have systematically examined the effect of varying material thickness ratio. Here, we study through-plane thermal conduction in lattice-matched In{sub 0.53}Ga{sub 0.47}As/In{sub 0.52}Al{sub 0.48}As SLs grown by metalorganic chemical vapor deposition as a function of SL period thickness (4.2 to 8.4 nm) and layer thickness ratio (1:3 to 3:1). Conductivities are measured using time-domain thermoreflectance and vary between 1.21 and 2.31 W m{sup −1} K{sup −1}. By studying the trends of the thermal conductivities for large SL periods, we estimate the bulk conductivities of In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.48}As to be approximately 5 W m{sup −1} K{sup −1} and 1 W m{sup −1} K{sup −1}, respectively, the latter being an order of magnitude lower than theoretical estimates. Furthermore, we find that the Kapitza resistance between alloy layers has an upper bound of ≈0.1 m{sup 2} K GW{sup −1}, and is negligible compared to the intrinsic alloy resistances, even for 2 nm thick layers. A phonon Boltzmann transport model yields good agreement with the data when the alloy interfaces are modeled using a specular boundary condition, pointing towards the high-quality of interfaces. We discuss the potential impact of these results on the design and operation of high-power QCLs comprised of In{sub 1−x}Ga{sub x}As/In{sub 1−y}Al{sub y}As SL cores.

• OSTI ID: 22314699
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 5 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
CHEMICAL VAPOR DEPOSITION
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
KAPITZA RESISTANCE
PHONONS
SEMICONDUCTOR LASERS
THERMAL CONDUCTION