Characterization of a single-layer quantum wire structure grown directly on a submicron grating

Abstract

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.

High-resolution transmission electron microscopy studies of quantum wire structures grown on submicrometre gratings of V-grooves

“…It is therefore surprising how little work has been devoted to HRTEM studies of QWRs. We have previously presented HRTEM data of one of the structures used in this study in [34] and there have been at least two recent studies of QWRs using HRTEM [31,36]. Here we demonstrate how TEM, and especially HRTEM, can be useful to characterize QWR structures grown on V-grooved gratings.…”

“…There are three important ways of feeding the carriers into the QWR: directly from the barriers, from the quasi-{111} QWs and from the VQW. A study [34] of the carrier transfer within this structure used photoluminescence excitation spectroscopy (PLE), where the QWR emission is monitored and the wavelength of the excitation source is scanned to identify the different absorption contributions to the QWR emission. In the case of the contributions below the barrier energy, the largest contribution was found to be the VQW and not the quasi-{111} QWs as expected [45].…”

“…The optical properties of these QWRs are generally characterized by photoluminescence (PL) [14,24,25,30,33,34] and cathodoluminescence (CL) [28,[31][32][33][34][35], the structural properties are characterized by scanning electron microscopy [14,28,33] and transmission electron microscopy (TEM) [22,26,27,30,31,34,35]. Most of the TEM investigations have been devoted to bright field (BF) imaging and dark field (DF) imaging.…”

Temperature dependence on the emerging crystal habit of GaInP deposited on nonplanar {001}GaAs substrates

“…For example, quantum dots [28,29], which results from exploring the Stranski-Krastonow growth mode, are features bounded by {113} type facets. Compositional gradients [30][31][32] might be used in order to laterally define a structure by doping levels which can be appreciably higher [33,34] than is ordinarily achieved on lower indexed faces. These structures might also be used to explore the segregation of various doping species in co-doped samples [25,35] or examine the amphoteric [36] character of Si in defining lateral p-n junctions.…”

Exact solution for 2D polygonal inclusion problem in anisotropic magnetoelectroelastic full-, half-, and bimaterial-planes

“…Finally, we study the 'classic' V-shaped QWR structure (Kapon et al, 1989;Rinaldi et al, 1994;Gustafsson et al, 1994Gustafsson et al, , 1996Grundmann et al, 1994;Goldoni et al, 1996;Rossi et al, 1997Rossi et al, , 1999 in the semiconductor full-plane using our solutions. The V-shaped QWR has a crescent cross section (Fig.…”