Optical phonon interaction effects in layered semiconductor structures
Abstract
Various aspects of the electronLOphonon interaction effects on the electronic properties of a single twodimensional electron layer (as occurring, for example, in artificially structured single quantum wells or heterojunctions made of IIIV or IIVI semiconducting materials) are discussed theoretically. In particular, perturbation theory is carried to the second order in the coupling constant to obtain the twodimensional polaron energy in the weakcoupling limit. Intermediate coupling (the socalled LeeLowPines theory) and strong coupling theories for the twodimensional polaron problem are developed and interpolation (Padé approximations) formulae valid for arbitrary coupling are derived. Effects of the band nonparabolicity and of the freecarrier screening on the weakcoupling theory are discussed. The real and the imaginary parts of the twodimensional polaron selfenergy are obtained in a manybody perturbation calculation. Comparison with the known threedimensional results is made wherever possible, showing that the electronLOphonon interaction effects are substantially enhanced in confined structures. Explicit formulas valid for twodimensional systems are given for various polaron parameters like the binding energy, the effective mass, the scattering rate, the average phonon density in the polaron cloud, etc.
 Publication:

Annals of Physics
 Pub Date:
 August 1985
 DOI:
 10.1016/00034916(85)903513
 Bibcode:
 1985AnPhy.163...78S