Fyzikální ústav Akademie věd ČR

Vznik excitonu, jeho transfer a rekombinace v polovodičových vrstvách a kvantových tečkách

Seminář Středa, 28.03.2012 13:00 - 14:00

Přednášející: Dr. Konstantin Zhuravlev (Institute of Semiconductor Physics, Siberian branch of Russian Academy of Sciences,13, Lavrentiev avenue, 630090, Novosibirsk, Russia)
Místo: Zasedací místnost bodova A, Cukrovarnická 10, Praha 6
Jazyk: anglicky
Pořadatelé: Oddělení optických materiálů

The talk comprises a few novels concerning different aspects of exciton formation, transport and recombination in semiconductor heterostructures. First, results of experimental study of exciton formation in bulk AlGaAs layers by analyzing dynamics of an energy splitting between excitons with spins +1 and -1 created by circularly polarized light, in the absence of any magnetic field will be presented. Then, the dynamics of exciton recombination in an ensemble of indirect band-gap (In,Al)As/AlAs quantum dots with type-I band alignment will be discussed. It will be shown that the lifetime of confined excitons that are indirect in momentum space is mainly influenced by the sharpness of the heterointerface between the (In,Al)As quantum dot and the AlAs barrier matrix. At last, an energy transfer issue in composite structures consisting of carbon nanotubes and CdS semiconductor quantum dots will be considered. Two mechanisms of carriers leaving from quantum dots can be considered: tunneling and fluorescence resonance energy transfer.

Copyright © 2008-2010, Fyzikální ústav AV ČR, v. v. i.