Formation of spatial patterns in the photoluminescence ofAlGaAs/GaAs heterojunctions in quantizing magnetic fields

摘要

Photoluminescence of a remotely doped GaAlAs/GaAs-heterojunction is found to becomestrongly inhomogeneous in space, if a quantizing magnetic field, perpendicular to the junction,and an external current are simultaneously applied to the sample. Typically, a stripe ofquenched photoluminescence arises adjacent to one of the sample edges. An analogous darkstructure has been observed on a variety of samples. It is characterized a.o. by the followingfeatures: it has well defined, sharp contours; its width varies synchronously with Shubnikov-deHaas oscillations; its location reflects the direction of the Lorentz force; the structure becomesunstationary if the current approaches the critical current of the breakdown of the quantum-Hall-regime.