Transition from two-dimensional electron-hole to geminate-exciton photoluminescence in GaAs/AlxGa1-xAs heterostructures under a high in-plane magnetic field

We studied the evolution of the photoluminescence (PL) spectra in modulation-doped GaAs-based heterostructures (single quantum wells and heterojunctions) at T-L=1.2 K under a high magnetic field B (up to 33 T), which was applied parallel to the two-dimensional electron gas (2DEG) layer. Under low in-plane fields, B-parallel to