Abstract
We show that the tunnel emission of electrons out of a single quantum well into an As conduction band under a perpendicular electric field can be observed by transient-capacitance spectroscopy in the 0.1–100-ms time range. This has been made possible by the use of a semiconductor-insulator-semiconductor-type structure where the GaAs space-charge probe region is separated from the quantum well by a thin As barrier. The variation of the tunneling time with applied electric field is in good agreement with a simple Fowler-Nordheim model. The absolute values of the tunneling time are, however, significantly different from the expected theoretical values. The origin of this discrepancy is briefly discussed.
- Received 7 February 1991
DOI:https://doi.org/10.1103/PhysRevB.44.3157
©1991 American Physical Society