We report a persistent increase or decrease in the two-dimensional electron density of AlAs or GaAs quantum wells flanked by AlxGa1-xAs barriers, brought about by illuminating the samples at T ∼ 4 K, while simultaneously applying a voltage bias between a back gate and the two-dimensional electron gas. Control of the final carrier density is achieved by tuning the back gate bias during illumination. Furthermore, the strength of the persistent photoconductivity depends on the Al mole fraction in the back AlxGal1-xAs barrier, and is largest at x ≅ 0.4.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Apr 1 2003|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics