Publication
Physical Review B
Paper

Picosecond imaging of photoexcited carriers in quantum wells: Anomalous lateral confinement at high densities

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Abstract

We have measured the in-plane motion of photoexcited carriers in semiconductor quantum wells and have discovered several surprising results. The effective diffusivity of the carriers at densities below n=2×1011 cm-2 is found to depend upon the excitation level, possibly indicating defect-limited diffusion or phonon-wind effects. Above this density the spatial profiles exhibit two distinct components with widely differing diffusivities. We postulate that the slowly diffusing component represents carriers which are "thermally confined" to a phonon hot spot. © 1988 The American Physical Society.

Date

15 Sep 1988

Publication

Physical Review B