Carrier Relaxation in InGaAs-GaAs Quantum Dots Formed by Activated Alloy Phase Separation
RUSSIAN ACADEMY OF SCIENCES SAINT PETERSBURG IOFFE PHYSICAL-TECHNICAL INST
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Structures with InGaAs-GaAs quantum dots QDs formed by activated alloy phase separation have been studied by resonant photoluminescence. Near resonant PL at 20 K reveals a series of broad phonon replicas. This line width is explained by multiphonon relaxation processes involving LO phonons in the QDs, the wetting layer, interface, and GaAs as well as by additional scattering by acoustic phonons. The complex distribution of InGaAs in QDs formed by activated alloy phase separation is believed to cause a dispersion of QD phonon energies and to lead to a further broadening of phonon lines. For the sample with high QD confinement energy the photoluminescence line shape depends on the excitation wave length for near resonant excitation even at room temperature, which suggests non-Fermi carrier distribution in the QD array.
- Solid State Physics