Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 49: Quantum dots: preparation and characterization
HL 49.5: Vortrag
Freitag, 27. März 2009, 11:15–11:30, BEY 81
Structure of InAs/InGaAsP/InP Quantum Dots/Dashes — •Florian Genz1, Andrea Lenz1, Lena Ivanova1, Rainer Timm1, Udo W. Pohl1, Dieter Franke2, Harald Künzel2, Holger Eisele1, and Mario Dähne1 — 1Technische Universität Berlin, Institut für Festkörperphysik, Germany — 2Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut, Germany
Quantum dots or dashes in the InAs/InGaAsP/InP heterostructure system with emission wavelengths matching the absorption minimum of silica fibers (1.55 µm) are promising for semiconductor optical amplifiers for optical data transmission. To improve the device design and the preparation method, a detailed knowledge of the capped nanostructures is of high importance.
The size, shape, and density of InAs/InGaAsP quantum dots/dashes grown by metal organic vapor phase epitaxy were investigated with cross-sectional scanning tunneling microscopy (XSTM). We will present atomically resolved XSTM images of both the (110) and the (110) cleavage surface showing a lateral decomposition of the quaternary InGaAsP matrix which may affect quantum dash development. The evolved nanostructures have lateral sizes of 14 to 33 nm base length along [110] and of 7 to 17 nm along [110] while their heights are about 1.7 nm for the specific growth conditions applied. These structural results will be discussed under consideration of the growth conditions.
This work was supported by Sfb 787 TP A3 and A4 of the DFG.