Anisotropic thermal conductivity of Ge quantum-dot and symmetrically strained Si/Ge superlattices.

Thermal conductivity of symmetrically strained Si/Ge superlattices

This paper reports temperature-dependent thermal conductivity measurements in the crossplane direction of symmetrically strained Si/Ge superlattices, and the effect of doping, period thickness and dislocations on the thermal conductivity reduction of Si/Ge superlattices. The Si/Ge superlattices are grown by molecular beam epitaxy on silicon and siliconon-insulator substrates with a graded buffe...

Cross-plane thermal conductivity of self-assembled Ge quantum dot superlattices

The self-assembled quantum dot structure is an interesting topic for physical investigation of zero-dimensional system. Due to the low-dimensional confinement effect, the Ge-on-Si quantum dot structure is expected to demonstrate novel optoelectronic properties that can be applied to develop Sibased technology competitive with traditional optoelectronic materials such as III-V compounds. In addi...

Electrical and Thermal Conductivity of Ge/Si Quantum Dot Superlattices

Recently proposed thermoelectric applications of quantum dot superlattices made of different material systems depend crucially on the values of the electrical and thermal conductivities in these nanostructures. We report results of the measurements of Hall mobility and thermal conductivity in a set of Ge0.5Si0.5/Si quantum dot superlattices. The average measured in-plane Hall mobility for the u...

Reduction of lattice thermal conductivity in one-dimensional quantum-dot superlattices due to phonon filtering

One dimensional quantum-dot superlattices (1D-QDSLs) consisting of acoustically mismatched materials are demonstrated theoretically to possess sub-1 W m−1 K−1 thermal conductivity in the 50–400 K range of temperatures. We consider coherent Si/Ge 1D-QDSLs, as well as model Si/plastic, Si/SiO2 and Si/SiC 1D-QDSLs. The phonon energy spectra and group velocities are obtained in the framework of the...

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