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We present cathodoluminescence (CL) investigations of a corrugated GaAs/AlGaAs single quantum well (QW) structure grown on a submicron grating. The CL spectra have four distinct emission peaks. Using plan-view and cross-sectional CL imaging together with cross-sectional transmission electron microscope imaging, we have assigned the four peaks: They originate in the nominal QW, a quantum wire (QWR), a vertical quantum well (VQW), and the barrier, respectively. We have CL-imaged and -characterized single QWRs and VQWs.

N-doped vertical AlGaAs quantum wells have been fabricated by metalorganic vapor phase epitaxial growth of a single-doped AlGaAs layer on a submicron grating. Intersubband absorption at normal incidence is demonstrated in those quantum wells. This opens new possibilities for infrared quantum well devices using intersubband transitions.

Articles you may be interested inElectronic structure of a single-layer InN quantum well in a GaN matrix Cathodoluminescence of single quantum wires and vertical quantum wells grown on a submicron grating A single AlGaAs/GaAs quantum well ͑QW͒/quantum wire ͑QWR͒ structure was grown by metalorganic vapor phase epitaxy on a submicron period grating of V grooves. High resolution transmission electron microscopy studies of the sample identifies three regions of the QW; between the grooves, approximately 3.5 nm thick and oriented along ͑100͒, on the sidewalls of the V groove slightly thinner and oriented along ͕111͖. At the bottom of the groove an approximately 70 nm wide crescent shaped region forms a QWR. In addition, a vertical quantum well ͑VQW͒ extends from the bottom of each V groove in the GaAs substrate to the surface. The luminescence spectra of the sample are dominated by a peak originating in the QW, with additional peaks of the QWR, the VQW and the AlGaAs barrier. The striped nature of the sample is revealed in the top view cathodoluminescence ͑CL͒ images of all four peaks. In side view CL images, the QWR emission appears spot like, whereas the emission of the VQW is elongated in the direction perpendicular to the surface. Photoluminescence excitation spectroscopy reveals that the main source for excitation in the QWR comes from the VQW, even though a small contribution comes from the QW.

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