Photoreflectance characteristics of AlGaAs/GaAs structures

Room temperature photoreflectance (PR) has been used to study a series of AlGaAs/GaAs heterostructures, which have been shown by electrical measurements to contain a two- dimensional electron gas (2-DEG), with varying carrier concentrations, mobilities, and structures. Oscillatory features in the PR spectra observed above the GaAs bandgap energy cannot be simply interpreted as Franz-Keldysh oscillations (FKO).