ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The effects of a degenerate two-dimensional electron gas on the interband optical excitations, occurring in the active channel of Al0.32Ga0.68As/In0.15Ga0.85As/GaAs high electron mobility transistor structures, were investigated by using phototransmittance spectroscopy. The ground state transition at room temperature exhibited a characteristic steplike line shape, which was considered to be an effect of the screening of excitons by the degenerate electron gas. A line shape fitting by using a first derivative of the absorption coefficient with respect to the electron sheet concentration ns, allowed an estimation of the latter quantity by phototransmittance. An observed temperature-sensitive excitonlike signal, associated with the second electron subband was attributed to the modulation of the many-body correlation-enhanced excitonic absorption, known as the Fermi-edge singularity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.109695
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