19 November 1993 Exciton-polariton resonances in light absorption spectra of semiconductor superlattices and crystals
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Proceedings Volume 1985, Physical Concepts and Materials for Novel Optoelectronic Device Applications II; (1993) https://doi.org/10.1117/12.162811
Event: Physical Concepts of Materials for Novel Optoelectronic Device Applications II, 1993, Trieste, Italy
Abstract
The absorption-edge spectra have been studied in the temperature range from 4 to 300 K for single-crystal CdTe, ZnTe, GaAs wafers and GaAs/(Al,Ga)As multiple quantum well (MQW) structures. In all cases the frequency integrated absorption coefficient K is found to increase monotonously with temperature T up to T = T* and to keep constant above T*. The temperatures T*, depending on semiconducting materials, might be considered as critical ones corresponding to a change in polaritonic ener~ transport mechanism due to the lack of spatial dispersion at T<T*. It was shown, that though the measured temperatures T -. o2 K correspond to much larger linewidths than could be explained by using the theoretical value of the exciton damping parameter, this discrepancy can be overcome if a temperature-dependent inhomogeneous broadening is taken into account consistently. A similar temperature dependence of K with T* = 20 K has been observed for the first time in GaAs/( Al, Ga)As MQW-structures.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ruben P. Seisyan, Vladimir A. Kosobukin, S. A. Vaganov, G. N. Aliev, O. S. Coschug, "Exciton-polariton resonances in light absorption spectra of semiconductor superlattices and crystals", Proc. SPIE 1985, Physical Concepts and Materials for Novel Optoelectronic Device Applications II, (19 November 1993); doi: 10.1117/12.162811; https://doi.org/10.1117/12.162811
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