scholarly journals Influence of isotopic composition of silicon on local vibrational modes of vacancy-oxygen complex

2021 ◽  
pp. 102-110
Author(s):  
Ekaterina A. Tolkacheva ◽  
Vladimir P. Markevich ◽  
Leonid I. Murin
Keyword(s):  
Isotopic Composition ◽  
Room Temperature ◽  
Oxygen Impurity ◽  
Vibrational Modes ◽  
Absorption Bands ◽  
Impurity Atoms ◽  
Oxygen Complex ◽  
Isotopic Shifts ◽  
Oxygen Center ◽  
Local Vibrational Modes

Isotopic composition of natural silicon (28Si (92.23 %), 29Si (4.68 %) and 30Si (3.09 %)) affects noticeably the shape of infrared absorption bands related to the oxygen impurity atoms. The positions of local vibrational modes (LVMs), related to quasimolecules 28Si – 16OS – 29Si and 28Si – 16OS – 30Si (OS – substitutional oxygen atom) have been determined for the absorption spectra measured at Т ≅ 20 K and at room temperature (Т ≅ 300 K). An estimation of the isotopic shifts of corresponding modes in a semi empirical way has been done by the fitting the shape of the experimentally measured absorption band related to the vacancy-oxygen center in irradiated Si crystals. The LVM isotope shifts at Т ≅ 300 K are found to be (2.22 ± 0.25) сm–1 for 28Si – 16OS – 29Si and (4.19 ± 0.80) сm–1 for 28Si – 16OS – 30Si in relation to the most intense band with its maximum at (830.29 ± 0.09) cm–1 due to the vibrations of  28Si – 16OS – 28Si, and the full width at half maximum of the A-center absorption bands is (5.30 ± 0.26) cm–1. At Т ≅ 20 K the corresponding values have been determined as (1.51 ± 0.13); (2.92 ± 0.20); (835.78 ± 0.01) and (2.34 ± 0.03) сm–1. A model for the calculation of isotopic shifts in the considered case has been discussed. From an analysis of the observed isotopic shifts some information about the structure of the vacancy-oxygen complex in silicon at Т ≅ 20 K and at room temperature has been obtained.

LOCAL VIBRATIONAL MODES AND THE OPTICAL ABSORPTION TAIL OF AMORPHOUS SILICON

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4261-4266 ◽  
Author(s):  
P. K. LIM ◽  
W. K. TAM
Keyword(s):  
Optical Absorption ◽  
Amorphous Silicon ◽  
Research Area ◽  
Amorphous Semiconductor ◽  
Optical Absorption Coefficient ◽  
Vibrational Modes ◽  
Impurity Atoms ◽  
Radio Frequency Sputtering ◽  
Important Research Area ◽  
Local Vibrational Modes

Local vibrational modes of Si - H is an important research area in recent years. Local vibrational modes of chemical bonds between Si atom and other impurity atoms such as H and O in amorphous silicon films produced by radio frequency sputtering were studied by means of Fourier transform infrared spectroscopy. The concentrations of Si - H , Si - O and Si - C in the sample were calculated. It was found that the concentration of Si - H bond varied significantly when the material was annealed at temperatures Ta >600 K and tended to zero for Ta >1000 K . The optical absorption edge was also found to depend strongly on the thermal history of the amorphous semiconductor. A strong correlation between the optical absorption coefficient and the concentration of Si - H was also observed.

Anomalous vibrational modes in acetanilide as studied by inelastic neutron scattering

1992 ◽  
Vol 2 (10) ◽  
pp. 1929-1939 ◽  
Author(s):  
Mariette Barthes ◽  
Juegen Eckert ◽  
Susanna W. Johnson ◽  
Jacques Moret ◽  
Basil I. Swanson ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Vibrational Modes

LUMINESCENCE AND DEEP LEVEL STUDIES OF LINE DISLOCATIONS IN GALLIUM PHOSPHIDE

1983 ◽  
Vol 44 (C4) ◽  
pp. C4-233-C4-241
Author(s):  
B. Hamilton ◽  
A. R. Peaker ◽  
D. R. Wight
Keyword(s):  
Gallium Phosphide ◽  
Deep Level
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