scholarly journals Образование нанокристаллов кремния при трении

2020 ◽  
Vol 62 (7) ◽  
pp. 1070
Author(s):  
В.И. Веттегрень ◽  
Р.И. Мамалимов ◽  
И.П. Щербаков ◽  
В.Б. Кулик
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystal ◽  
Time Dependence ◽  
Silicon Nanocrystals ◽  
Time Interval ◽  
Pl Spectra ◽  
Linear Dimensions ◽  
Superimposed Signals ◽  
Twofold Decrease

Abstract It is found using triboluminescence (TL) that nanocrystals of silicon (ncSi) with linear dimensions of about 4 nm are formed from a single crystal of silicon (Si) under friction. The time dependence of the intensity of TL signals is investigated. It consists of many superimposed signals. An analysis of their dynamics shows that nanocrystals are located on the microcrack faces formed during fracture. At the same time, a powder flies out of the friction region. Using the photoluminescence (PL) and Raman spectroscopy methods, the size of silicon nanocrystals in the powder was determined. It is about 2.2 nm. Probably, microcracks grow further in the time interval between friction and recording the Raman and PL spectra (several hours), which leads to an approximately twofold decrease in the size of nanocrystals.

Local strain evaluation of single crystal Si pillar by micro Raman spectroscopy and photoluminescence

2008 ◽  
Vol 517 (1) ◽  
pp. 31-33 ◽  
Author(s):  
Dong Wang ◽  
Hiroshi Nakashima ◽  
Masanori Tanaka ◽  
Taizoh Sadoh ◽  
Masanobu Miyao ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystal ◽  
Local Strain ◽  
Micro Raman Spectroscopy

Radiation spectrum of hot excitons in Si nanocrystals

2016 ◽  
Vol 55 (4) ◽  
Author(s):  
Anton V. Gert ◽  
Irina N. Yassievich
Keyword(s):  
Energy Distribution ◽  
Silicon Nanocrystals ◽  
Energy Exchange ◽  
Relaxation Times ◽  
Exciton State ◽  
Time Interval ◽  
Pump Probe ◽  
Si Nanocrystals ◽  
Wide Energy ◽  
Probe Spectroscopy

The self-trapped exciton state (STE) is very important for the dynamics of hot excitons in photoexcited silicon nanocrystals embedded in a SiO2 matrix. This fact has been recently confirmed by the experimental data obtained by the femtosecond pump– probe spectroscopy technique in Amsterdam University. In this work we have studied the energy exchange between the exciton localized in the STE state and the hot exciton in the core of silicon nanocrystals and have shown that it determines the dynamics of the energy distribution of the hot excitons. Using the Monte-Carlo we have simulated the energy distribution of excitons in the time interval 10–100 ps after excitation. Thus the model of formation of the distribution of hot excitons in silicon nanocrystals is developed and the fast formation of the wide energy distribution is demonstrated. The form of the photoluminescence spectrum almost directly corresponds to the energy distribution of excitons in a silicon nanocrystal at a given moment. In the result we have found the relaxation times of hot excitons equal to 100 ps and the inner quantum efficiency of the ultrafast photoluminescence of about 0.1%. These values are close to the experimentally observed ones.

Probing the Subtle Magnetic Transitions with Raman Spectroscopy in a Bi-layered La1.15Sr1.85Mn2O7 Single Crystal

2019 ◽  
Vol 32 (12) ◽  
pp. 3939-3945
Author(s):  
M. Egilmez ◽  
N. M. Hamdan ◽  
H. Alawadhi ◽  
M. S. AlGhabra ◽  
D. Prabhakarian
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystal ◽  
Magnetic Transitions

scholarly journals Interfacial potassium induced enhanced Raman spectroscopy for single-crystal TiO2 nanowhisker

2020 ◽  
Vol 28 (3) ◽  
pp. 889-895 ◽  
Author(s):  
Fan Pan ◽  
Guobing Zhou ◽  
Liangliang Huang ◽  
Wei Li ◽  
Mingshen Lin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystal
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