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.

scholarly journals Local vibrational modes of vacancy-oxygen-related complexes at room temperature

2020 ◽  
Vol 56 (4) ◽  
pp. 480-487
Author(s):  
E. A. Tolkacheva ◽  
V. P. Markevich ◽  
L. I. Murin
Keyword(s):  
Absorption Band ◽  
Room Temperature ◽  
Clear Correlation ◽  
Ir Absorption ◽  
Oxygen Impurity ◽  
Interstitial Oxygen ◽  
Vibrational Modes ◽  
Oxygen Defect ◽  
Absorption Bands ◽  
Local Vibrational Modes

The isotopic content of natural silicon (28Si (92.23 %), 29Si (4.68 %) и 30Si (3.09 %)) affects noticeably the shape of IR absorption bands related to the oxygen impurity atoms. In the present work an attempt is undertaken to determine the positions of local vibrational modes (LVMs), related to quasimolecules 28Si16OS29Si and 28Si16OS30Si (OS – substitutional oxygen atom), for the absorption spectra measured at room temperature. An estimation of the isotopic shifts of corresponding modes is done by fitting the shape of the experimentally measured absorption band related to the vacancy–oxygen center in irradiated Si crystals. The LVM isotope shifts are found to be equal 2,2 ± 0.25 cm–1 for 28Si-16OS29Si and 4,3 ± 0,9 см–1 for 28Si-16OS30Si in relation to the basic band due to 28Si-16OS28Si, and the full width at half maximum of the A-center absorption band (28Si-16OS28Si) is 5,3 ± 0.25 cm–1. By means of infrared absorption spectroscopy a clear correlation between the disappearance of the divacancy (V2) in the temperature range 200–275 ºС and appearance of two absorption bands with their maxima at 825.8 and 839.2 cm–1 in irradiated oxygen-rich Si crystals is found. The band positioned at 825.8 cm–1 is assigned to a divacancy-oxygen defect V2O formed via an interaction of mobile V2 with interstitial oxygen (Oi ) atoms. The 839.2 cm–1 band is much more pronounced in neutron irradiated samples as compared to samples irradiated with electrons. We argue that it is related to a trivacancy–oxygen defect (V3O) formed via an interaction of mobile V3 with Oi atoms.

scholarly journals Оптические свойства и механизм образования вакансионно-кислородных комплексов V-=SUB=-2-=/SUB=-O-=SUB=-2-=/SUB=- и V-=SUB=-3-=/SUB=-O-=SUB=-2-=/SUB=- в облученных кристаллах кремния

2018 ◽  
Vol 52 (9) ◽  
pp. 973
Author(s):  
Е.А. Толкачева ◽  
В.П. Маркевич ◽  
Л.И. Мурин
Keyword(s):  
Infrared Absorption ◽  
Vibrational Modes ◽  
Fourier Spectroscopy ◽  
Absorption Bands ◽  
Fast Electrons ◽  
Czochralski Silicon ◽  
Silicon Crystals ◽  
Local Vibrational Modes ◽  
Oxygen Complexes

AbstractThe processes of the formation and annealing of V_ n O_ m ( n , m ≥ 2) vacancy–oxygen complexes in Czochralski silicon crystals irradiated with fast electrons and reactor neutrons have been studied by infrared absorption Fourier spectroscopy. A number of arguments are presented in favor of identification of absorption bands at 829.3 and 844.2 cm^–1 as being related to local vibrational modes of V_2O_2 and V_3O_2 complexes, respectively.

Carrier Doping of Silicon Nanowires Synthesized by Laser Ablation

2006 ◽  
Vol 963 ◽  
Author(s):  
Naoki Fukata ◽  
Naoya Okada ◽  
Satoshi Matsushita ◽  
Takao Tsurui ◽  
Shun Ito ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Silicon Nanowires ◽  
Optical Phonon ◽  
Room Temperature ◽  
Vibrational Modes ◽  
Scattering Measurements ◽  
Doped Silicon ◽  
Phonon Peak ◽  
Local Vibrational Modes ◽  
Carrier Doping

ABSTRACTBoron (B) doped silicon nanowires (SiNWs) were synthesized by laser ablation. Local vibrational modes of B in SiNWs were observed by micro-Raman scattering measurements at room temperature. Broadening due to a coupling between the discrete optical phonon and a continuum of interband hole excitations was also observed in the Si optical phonon peak. This is called Fano broadening. These results prove that B atoms were doped in substitutional sites of crystalline Si core of SiNWs during laser ablation.

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.

scholarly journals Spectral Dependence of Optical Absorption of 4H-SiC Doped with Boron and Aluminum

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
I. G. Atabaev ◽  
Kh. N. Juraev ◽  
M. U. Hajiev
Keyword(s):  
Optical Absorption ◽  
Spectral Dependence ◽  
Room Temperature ◽  
Aluminum Silicate ◽  
Absorption Bands ◽  
Vacancy Defects ◽  
Impurity Atoms ◽  
Temperature Diffusion ◽  
First Time ◽  
Diffusion Of Impurities

Optical absorption of p-n-4H-SiC structures doped with boron and aluminum by low-temperature diffusion was studied for the first time. Diffusion of impurities was performed from aluminum-silicate and boron-silicate films (sources) fabricated by various methods. In the spectral dependences of optical absorption at room temperature, bands associated with transitions from impurity levels, as well as absorption bands associated with defects of the vacancy nature, were observed. The level of absorption in the samples was used to estimate concentration of defects. It was shown that the use of sources of impurity atoms created by using boron and aluminum chlorides allows one to reduce the concentration of vacancy defects.

scholarly journals Local vibrational modes of interstitial boron-interstitial oxygen complex in silicon

2016 ◽  
Vol 213 (11) ◽  
pp. 2850-2854 ◽  
Author(s):  
L. I. Murin ◽  
S. B. Lastovskii ◽  
E. A. Tolkacheva ◽  
V. P. Markevich ◽  
A. R. Peaker ◽  
...  
Keyword(s):  
Interstitial Oxygen ◽  
Vibrational Modes ◽  
Oxygen Complex ◽  
Local Vibrational Modes

High Energy Local Vibrational Modes of Carbon Aggregates in SiC: Experimental and Theoretical Insight

2006 ◽  
Vol 527-529 ◽  
pp. 465-468 ◽  
Author(s):  
Alexander Mattausch ◽  
M. Bockstedte ◽  
Oleg Pankratov ◽  
John W. Steeds ◽  
S.A. Furkert ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
High Energy ◽  
Vibrational Modes ◽  
Energy Mode ◽  
Local Vibrational Modes ◽  
Theoretical Insight

We observe new photoluminescence centers in electron-irradiated 6H-SiC with phonon replicas up to 250 meV and clear threefold isotope splitting of the highest energy mode. Based on ab initio calculations, we discuss the tri-carbon anti-site (C3)Si and the di-interstitial (C2)Hex as models for these centers.

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