1. Real-space transfer and current filamentation in AlGaAs/GaAs heterojunctions subjected to high-electric fields
- Author
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Wolter, Joachim H., Haverkort, Jos E., Hendriks, Peter, Zwaal, E.A.E., Ferry, David K., van Driel, Henry M., and Photonics and Semiconductor Nanophysics
- Subjects
Condensed Matter::Materials Science - Abstract
At high electric fields negative differential resistance and oscillatory behavior of the current is observed in 2-dimensional electron gases in modulation doped heterostructures. We develop a model in which the understanding of these phenomena is provided by the ohmic contacts to the 2-dimensional electron gas. The key phenomenon is that at a high electric field, well below the threshold field for real space transfer across the interface between the GaAs and the Al xGa1-xAs, injection of electrons from the contacts into the AlxGa 1-xAs layer opens a conductive channel in the AlxGa1-xAs parallel to the 2-dimensional electron gas in the GaAs layer. We show that avalanche ionization in the AlxGa1-xAs layer leads to current filamentation. We studied this behavior for various experimental conditions by means of a novel technique which we developed for this purpose: the technique of time resolved optical beam induced current.
- Published
- 1994