Journal
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
Volume 8, Issue 6, Pages 2955-2963Publisher
AMER SCIENTIFIC PUBLISHERS
DOI: 10.1166/jnn.2008.151
Keywords
Ge thin films; photoelectron spectroscopy; Raman spectroscopy; quantum confinement; structural properties
Ask authors/readers for more resources
In the present paper, we have investigated structural, optical as well as electronic properties of electron beam evaporated Ge thin films having layer thicknesses ranging from ultra-thin (5 nm) to thick (200 nm). The Raman spectra show that all peaks are shifted towards lower wave number as compared to their bulk counterparts and are considered as a signature of nanostructure formation and quantum confinement effect. The Raman line exhibits transformation from nanocrystalline to microcrystalline phase with a reduction in blue shift of peak position with increase in Ge film thickness (>5 nm). Similarly, the optical absorption spectra corresponding to these films also show reduction in blue shift effect, although Ge 5 nm film shows the absorption behaviour quite different from higher thickness films. The corresponding band gap values obtained from absorption measurements are much larger than bulk Ge and are mainly attributed to the effect of quantum confinement as expected for small size particles calculated from GIXRD patterns. AFM data in each case are correlated and discussed with structural as well as optical results to support the effect of growth morphology on the above-mentioned observations. The results are further supported by photoelectron spectroscopy (PES), photoluminescence (PL) and resistivity measurements and are interpreted in terms of crystallinity and quantum confinement effect.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available