Domain bistability in photoexcited GaAs multiple quantum wells

We report optical studies of stable electric-field domains in an undoped GaAs multiple-quantum-well p-i-n diode. Discontinuities and bistability due to jumps in the domain-wall position were observed in the photocurrent current-voltage characteristic. Simultaneous photoluminescence (PL) measurements confirm the presence of stable domains, and show that the bistability relates to the path history of the domain-wall location. From the PL measurements we have been able to calibrate the field strengths within the domains and determine the sheet charge density in the domain wall.