ISSN:
1573-4870
Keywords:
Germanium/silicon
;
superlattice
;
X-ray diffraction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Pure-Ge/Si short-period superlattice (SPS) samples consisting of 1.5-monolayer Ge and a 1.4- to 3.8-nm-thick Si layer grown by gas source molecular beam epitaxy (GS-MBE) were studied by double-crystal x-ray diffraction. For SPS with a Si layer less than 2.4 nm, the satellite peak caused by the SPS structure in the rocking curve is quite broad, and no fine structure is found, indicating that there exists dislocation and waviness epilayers in the SPS. For SPS with a thick Si layer, the rocking curve is sharp and fine interference structures exist, indicating smooth epilayers in the SPS. It is found that both broad and sharp peaks exist but without fine structure in the rocking curves for SPS samples with a Si layer thickness (L Si) in the range of 2.1–2.9 nm, which is the range in which an abnormal photoluminescence band appears in photoluminescence spectra. This result strongly supports H. Sunamura's suggestion that the abnormal photoluminescence band is caused by waviness formation of the epilayer due to vertical correlation of thickness fluctuations by the local strain field.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1021877415290
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