LO-phonons and excitons in (Cd,Zn)Te based quantum wells

Autor: R.P. Stanley, J. P. Doran, R.D. Feldman, John Hegarty
Rok vydání: 1993
Předmět:
Zdroj: Physica B: Condensed Matter. 191:71-82
ISSN: 0921-4526
Popis: We review the exciton properties of (Cd, Zn)Te based quantum well structures with the emphasis on LO phonon-exciton interactions. At low temperatures LO phonon emission is an important energy relaxation mechanism for excitons. Low spectral diffusion due to localization results in sharp line spectra. Spectral relaxation within localised exciton bands through LO phonon emission is described. The distinction between resonant Raman scattering and the sharp lines observed in these materials is made. At room temperature the width of the exciton resonance depends on the interaction between excitons and the thermal population of LO phonons. This interaction can be modified by changing the structure. LO phonon scattering causes rapid exciton ionization, yet free exciton luminescence can still be observed. The relative contributions to the absorption saturation due to free carriers and excitons is examined on a femtosecond time scale.
Databáze: OpenAIRE