Electron Scattering Interaction and Elementary Excitations in Lead Chalcogenides

Abstract

Dielectric properties and elementary excitations are discussed in lead chalcogenide semiconductors on the base of the RPA-dielectric function using a Kane-band model. Numerical and analytical results are presented for the dielectric function and the elementary excitation spectrum and compared with results for a parabolic model. A sum rule for the spectral function of the phonon propagator is given to calculate the phonon strength of elementary excitations.Es werden die dielektrischen Eigenschaften und Elementaranregungen in Blei-Chalkogenidhalbleitern auf der Grundlage eines Kaneschen Bandstrukturmodells untersucht. Numerische und analytische Resultate fur die RPA-dielektrische Funktion und das Spektrum der Elementaranregungen werden dargestellt und mit entsprechenden fur ein parabolisches Model1 verglichen. Zur Berechnung der Phononenstiirke der Elementaranregungen wird eine Summenregel fur die Spektralfunktion des Phononenpropagators abgeleitet.

Carrier Heating in Lead Chalcogenides

“…We assume that it depends on the mode character given by the phonon strength. As was shown in [15] there are a low-energy mode (ule and a high-energy mode (uhe different in character. If the carrier concentration is high enough ((up, oo > 1.5(u,~o) the high-energy mode is plasmon like.…”

“…We calculated the mean energy loss rate in dependence on temperature for PbSe (n, = 5.25 x 10'' T L = 4.2 K) according to (6) taking into account scattering on the low-energy mode and on acoustic phonons. The corresponding niode dispersion relations and coupling constants were taken from [15]. It can be seen from Fig.…”