1. Effect of interface defect formation on carrier diffusion and luminescence in In0.2Ga0.8As/AlxGa1−xAs quantum wells
- Author
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M. Meshkinpour, K. Rammohan, H. T. Lin, Y. Tang, Daniel H. Rich, and Mark S. Goorsky
- Subjects
Condensed matter physics ,Ambipolar diffusion ,Chemistry ,General Engineering ,Cathodoluminescence ,Diffusion (business) ,Dislocation ,Luminescence ,Anisotropy ,Quantum well ,Molecular beam epitaxy - Abstract
We have examined the influence of strain relaxation on the excitonic recombination and diffusion in In0.2Ga0.8As/AlxGa1−xAs quantum‐well (QW) samples designed for high‐electron‐mobility transistors, using spectrally and spatially resolved polarized cathodoluminescence (CL). Six molecular‐beam epitaxial grown samples, with varying channel thicknesses ranging from 75 to 300 A, were examined at various temperatures between 87 and 300 K. An increase in misfit dislocation density occurred with increasing channel thicknesses and resulted in changes in the dark line defect (DLD) density, polarization anisotropy, QW excitonic luminescence energy, and luminescence activation energy, as observed in CL. The influence of misfit dislocations on the ambipolar diffusion of excess carriers in a direction parallel to the dislocation line, in varying proximity to the DLDs, was examined with a CL‐based diffusion experiment. The temperature dependence of the CL imaging was examined, enabling a study of the spatial variation ...
- Published
- 1996