Diffusion thermopower of a p‐type Si/Si_1–xGe_x heterostructure at zero magnetic field

Abstract

We calculate the diffusion thermopower of the degenerate two-dimensional hole gas in a p-type Si/Si 1-x Ge x lattice mismatched heterostructure at low temperatures and zero magnetic field. The effects of possible scatterings, e.g. remote impurity, alloy disorder, interface roughness, deformation potential, and random piezoelectric on the hole mobility and the diffusion thermopower are examined. Calculated results are well fitted to the experimental data recently reported. In addition, we predict a possibility for the diffusion thermopower to change its sign as the SiGe layer thickness changes, the effect has not been discussed yet.

Intersubband carrier scattering inn- andp−Si∕SiGequantum wells with diffuse interfaces

“…16 The parameters, {∆=1.4 Å, Λ=50 Å} accurately fit the measurements and are very similar to our previous theoretical values, 16 and to other recent data. 13,18 The slight difference in fitting parameters arises from numerical approximations in the perturbing potentials: the perturbation for arbitrary interface geometries (Eqn. 2) uses a Taylor series expansion, whereas the solution for abrupt interfaces (Eqn.…”