Abstract
The carrier concentration of a two-dimensional electron gas in a quantum well was persistently reduced by red-light illumination at low temperature. The deep-level donors were “frozen out” at 50 K and the thermal activation energy was about 42.6 meV. We believe that these deep-level donors are unlikely centers, and the observed negative persistent photoconductivity probably arises from the trapping of electron by the empty localized state of random-local-potential fluctuations in the barrier.
- Received 11 December 1997
DOI:https://doi.org/10.1103/PhysRevB.57.R6819
©1998 American Physical Society