X-Ray Diffraction Analysis of Lateral Composition Modulation in InAs/GaSb Superlattices Intended for Infrared Detector Applications
NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
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Lateral compositional modulation in a InAs13GaSb13 superlattice grown by molecular beam epitaxy for infrared detector applications has been investigated using high resolution X-ray diffraction. X-ray diffraction reciprocal space maps exhibit distinct lateral satellite peaks about the vertical superlattice peaks however, the pattern is tilted with respect to the 001 direction. This tilt is directly related to the stacking of the layers as revealed by cross-sectional scanning tunnelling microscopy XSTM images. XSTM shows the morphology of the structure to consist of InAs- and GaSb-rich regions with a modulation wavelength of 1200A and a lateral composition wavelength of 554 - 3 A. The modulation only occurs along one in-plane direction, resulting in InAs nanowires along the 11 0 direction, which are several microns long.
- Infrared Detection and Detectors