Extremely high negative photoconductivity in <i>p</i>-modulation-doped GaAs quantum wells

Abstract

In p-modulation-doped quantum wells of GaAs/AlGaAs extremely high negative photoconductivity is observed at low temperatures. The in-plane sheet resistance can be increased by a factor of more than 60 with illumination of less than 1 W/cm2. Spectral analysis shows that the effect is mainly due to hole trapping in the potential minima of AlGaAs and subsequent recombination of minority electrons.