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Laser crystallization of germanium nanowires fabricated by electrochemical deposition
Author(s) -
Gavrilov Sergey A.,
Dronov Alexey A.,
Gavrilin Ilya M.,
Volkov Roman L.,
Borgardt Nickolay I.,
Trifonov Alexey Yu.,
Pavlikov Alexander V.,
Forsh Pavel A.,
Kashkarov Pavel K.
Publication year - 2018
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5353
Subject(s) - nanowire , raman spectroscopy , materials science , germanium , amorphous solid , nucleation , substrate (aquarium) , crystallization , laser , analytical chemistry (journal) , titanium , indium , silicon , optoelectronics , crystallography , chemical engineering , chemistry , optics , metallurgy , physics , oceanography , organic chemistry , engineering , chromatography , geology
Germanium (Ge) nanowires were fabricated by electrochemical deposition on titanium‐coated silicon substrate. Arrays of nanowires with different mean diameters were obtained using indium nanoparticles of various sizes as centers of nucleation. Raman spectroscopy was used to establish the structural properties of nanowires under different laser excitation intensities. Cycles of measurements with different intensities demonstrated irreversible changes in the structure. Initial study with minimal excitation intensity of 3 W/cm 2 displayed that the spectra are descriptive of amorphous Ge. Further study at increased intensities led to the transformation of Raman spectra to the shapes that can be attributed to crystalline Ge. Detailed analysis of spectra shapes for samples with different mean diameters of Ge nanowires after exposure to high intensity laser radiation allows to estimate the fraction of the crystalline phase in Ge nanowires. The spectra of a sample irradiated by He–Ne laser were compared with thermally annealed sample in a vacuum at 150 °C. A similar shape of the obtained spectra indicates on the thermal nature of the effect, which leads to a change in the observed structural properties. This change under even slight heating can be explained by thermal isolation of nanowires from the substrate.