In PbSe epitaxial thin films grown by thermal evaporation on KCl(001) substrates and covered with an EuS protective layer, oscillatory dependences of the galvanomagnetic and thermoelectric properties (electrical conductivity σ, the Hall coefficient RH, charge carrier mobility μ, and the Seebeck coefficient S) on the PbSe layer thickness d (3<d<200 nm) were observed at room temperature. Oscillations of the transport properties are associated with quantum size effects due to electron confinement in the PbSe quantum wells.

The dependencies of the thermoelectric properties of n-PbTe∕p-SnTe∕n-PbTe heterostructures on the SnTe quantum well width (dSnTe=0.5–6.0nm) at fixed PbTe barrier layers thicknesses were studied. It was established that the thickness dependencies of the Seebeck coefficient, electrical conductivity, the Hall coefficient, charge carrier mobility, and the thermoelectric power factor are distinctly nonmonotonic. The observed effect is attributed to the size quantization of the energy spectrum of the hole gas in a SnTe quantum well.

Oscillatory thickness dependences of the electrical conductivity, Hall coefficient, charge carrier mobility, and Seebeck coefficient were obtained at room temperature for n-type thin Bi films (d=3–300 nm) fabricated by the thermal evaporation of a bismuth crystal in a vacuum and deposition on mica substrates at 380 K. We attribute this oscillatory behavior to quantum-size effects, which are observable when the electron mean-free path and Fermi wave length exceed the film thickness d.

Oscillatory behaviour was detected in the dependences of the transport properties (electrical conductivity, Hall coefficient, charge carrier mobility, Seebeck coefficient and thermoelectric power factor) on the PbTe layer thickness d (d = 2–200 nm) in (001) KCl/PbTe/EuS quantum well (QW) structures at room temperature. The non-monotonic character of these dependences is attributed to quantum size effects, which manifest themselves in PbTe QWs at sufficiently small values of d. The positions of the extrema in the thickness dependences of the transport properties shift with changing electron concentration in PbTe QWs.

We report on the thickness d dependences of the Seebeck coefficient, electrical conductivity, and Hall coefficient of PbTe and PbS epitaxial thin films (d=5–200 nm), prepared by thermal evaporation in vacuum and deposition on (001) KCl substrates. The oxidation of the films in air at 300 K leads to a sign inversion of the carrier type from n to p in films with d⩽125 and 110 nm for PbTe and PbS, respectively. The observed d dependences are interpreted in terms of compensating acceptor states created by oxygen on the film surface.

No abstract

No abstract

Extrema were observed in the film thickness d dependence of various thermoelectric parameters (Seebeck coefficient S, electrical conductivity σ, Hall coefficient RH, charge carrier mobility μ, and power factor P) of epitaxial PbTe/(001) KCl thin films prepared by thermal evaporation in vacuum and protected from oxidation by an EuS layer. We attribute the observed extrema in properties and the high values of μ and P at d≈50 nm to the percolation transition from an island-like to a continuous film and to the self-organization of the islands, which can occur not only in quantum dot superlattices but also in an individual layer.