A long-lived persistent photoconductivity has been observed at low temperatures in thin, unintentionally doped Ga0.51In0.49P/GaAs quantum wells. The two-dimensional electron gas was studied by low field Hall and Shubnikov-de Haas measurements. Both the low field mobility and quantum scattering time increased with increasing carrier concentration after illumination with red light. The increase in carrier concentration is attributed to photoexcitation of carriers from a deep level located at 0.9 eV below the conduction band of InGaP. Parallel conduction due to extended illumination has also been observed in the anomalous behavior of the quantum Hall plateaus.
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering