Investigation of the H-band radiation in GaAs/AlGaAs heterostructures by photoluminescence and optically detected cyclotron resonance measurements

Abstract

With photoluminescence and optically detected cyclotron resonance measurements, we investigate broad emission bands, so-called H-bands in GaAs/AlGaAs heterostructures. The broad bands are due to the recombination between two-dimensional electrons in the interface notch and spatially separated holes in a GaAs layer. From excitation energy dependence of the radiation intensity of the H-band, transfer of the photoexcited holes from the AlGaAs to the GaAs is found to be important, when the excitation energy exceeds the band-gap energy of the AlGaAs. Under the excitation conditions, the observed peak positions of the H-band are highly dominated by the direct recombination in the real space between the two-dimensional electrons and the holes. By using the optically detected cyclotron resonance measurements, we can assign the H-band emission peak, when the H-band peak overlaps with the other emission peak.