PERSISTENT PHOTOCONDUCTIVITY IN AlGaAs-GaAs HETEROSTRUCTURES.

Persistent photoconductivity (PPC) is studied in modulation doped AlGaAs-GaAs heterostructures in the conductivity parallel to the heterojunctions. The results indicate that the macroscopic fields of the heterojunction and traps primarily in the GaAs rather than AlGaAs are responsible for the phenomenon. PPC is also reported in n** plus GaAs-undoped AlGaAs-n** plus GaAs heterostructures for current perpendicular to the heterojunctions.