Two-dimensional exciton dynamics and gain formation processes in InxGa1−xN multiple quantum wells
Year: 1999
Type: article
Abstract: We investigated exciton dynamics in ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}$ multiple quantum wells at 2 K and room temperature by means of time-resolved photoluminescence and pump-and-probe measurements. Under low excitation density, the temporal change of the spontaneous emission indicated slow dynamical features of the two-dimensional exciton localization, while, above a stimulation threshold density, the decay time of the emission was shortened to be less than $\ensuremath{\sim}30 \mathrm{ps}$ due to the stimulated emission process. Further, the time-resolved pump-and-probe measurement revealed a fast relaxation of photoexcited delocalized electron-hole $(e\ensuremath{-}h)$ pairs into localized states. Above stimulation threshold, localized states were saturated, and $e\ensuremath{-}h$ pairs at delocalized states were observed. Two-dimensional $e\ensuremath{-}h$ pairs at delocalized states relaxed into localized states and excitons were formed, from which the optical gain was formed in terms of the stimulated emission process.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1963527754