Зависимость характеристик узких линий люминесценции в наноалмазах от параметров возбуждения и температуры

The influence of the excitation parameters and temperature on the spectral characteristics of narrow photoluminescence lines in nanodiamonds obtained by chemical vapor deposition is investigated. It is shown that the ratio of the line intensities in the spectrum depends on the wavelength and power of the excitation radiation. For some lines, with increasing power, a shift in the position of their maximum and broadening is also observed. After irradiation of nanodiamonds with a laser beam with a power density of ~1.2·105 W/cm2, the relative line intensities change. With increasing temperature in the range 79 - 300 K, temperature quenching of their intensity is observed.

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Research on the Preparation and Spectral Characteristics of Graphene/TMDs Hetero-structures

Nanoscale Research Letters ◽

10.1186/s11671-020-03439-1 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Tao Han ◽

Hongxia Liu ◽

Shulong Wang ◽

Shupeng Chen ◽

Kun Yang

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Spectral Characteristics ◽

Graphene Film ◽

Chemical Vapor ◽

Chemical Vapor Deposition Method ◽

Si Substrate ◽

Broadband Absorption ◽

Gate Effect ◽

Pressure Chemical

AbstractThe Van der Waals (vdWs) hetero-structures consist of two-dimensional materials have received extensive attention, which is due to its attractive electrical and optoelectronic properties. In this paper, the high-quality large-size graphene film was first prepared by the chemical vapor deposition (CVD) method; then, graphene film was transferred to SiO2/Si substrate; next, the graphene/WS2 and graphene/MoS2 hetero-structures were prepared by the atmospheric pressure chemical vapor deposition method, which can be achieved by directly growing WS2 and MoS2 material on graphene/SiO2/Si substrate. Finally, the test characterization of graphene/TMDs hetero-structures was performed by AFM, SEM, EDX, Raman and PL spectroscopy to obtain and grasp the morphology and luminescence laws. The test results show that graphene/TMDs vdWs hetero-structures have the very excellent film quality and spectral characteristics. There is the built-in electric field at the interface of graphene/TMDs heterojunction, which can lead to the effective separation of photo-generated electron–hole pairs. Monolayer WS2 and MoS2 material have the strong broadband absorption capabilities, the photo-generated electrons from WS2 can transfer to the underlying p-type graphene when graphene/WS2 hetero-structures material is exposed to the light, and the remaining holes can induced the light gate effect, which is contrast to the ordinary semiconductor photoconductors. The research on spectral characteristics of graphene/TMDs hetero-structures can pave the way for the application of novel optoelectronic devices.

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Silicon homoepitaxy using tantalum-filament hot-wire chemical vapor deposition

MRS Proceedings ◽

10.1557/proc-862-a2.3 ◽

2005 ◽

Vol 862 ◽

Cited By ~ 5

Author(s):

Charles W. Teplin ◽

Eugene Iwaniczko ◽

Kim M. Jones ◽

Robert Reedy ◽

Bobby To ◽

...

Keyword(s):

Electron Microscopy ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Secondary Ion Mass Spectrometry ◽

Chemical Vapor ◽

Silicon Wafers ◽

Silicon Films ◽

Hot Wire ◽

Transmission Electron ◽

Increasing Temperature

AbstractWe have studied silicon films grown epitaxially on silicon wafers using hot-wire chemical vapor deposition (HWCVD) with a tantalum filament. Silicon films were grown on (100)-oriented hydrogen terminated silicon wafers at temperatures from 175°C to 480°C, using a Ta filament 5 cm from the substrate to decompose pure SiH4 gas. The progression of epitaxy was monitored using real-time spectroscopic ellipsometry (RTSE). Analysis using RTSE, transmission electron microscopy (TEM), and scanning electron microscopy shows that at a characteristic thickness, hepi all of the films break down into a-Si:H cones. Below 380°C, both hepi and the thickness of the transition to pure a-Si:H increase with increasing temperature. Above 380°C, hepi was not observed to increase further but TEM images show fewer defects in the epitaxial regions. Secondary ion-mass spectrometry shows that the oxygen concentration remains nearly constant during growth (<1018 cm-3). The hydrogen concentration is found to increase substantially with film thickness from 5·1018 to 5·1019 cm-3, likely due to the incorporation of hydrogen into the a-Si:H cones that grow after the breakdown of epitaxy.

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Reduced temperature-quenching of photoluminescence from indium nitride nanotips grown by metalorganic chemical vapor deposition

Applied Physics Letters ◽

10.1063/1.2128484 ◽

2005 ◽

Vol 87 (20) ◽

pp. 203103 ◽

Cited By ~ 18

Author(s):

Shih-Chen Shi ◽

Chia-Fu Chen ◽

Geng-Ming Hsu ◽

Jih-Shang Hwang ◽

Surojit Chattopadhyay ◽

...

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Metalorganic Chemical Vapor Deposition ◽

Indium Nitride ◽

Chemical Vapor ◽

Temperature Quenching ◽

Reduced Temperature ◽

Metalorganic Chemical

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In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100137653 ◽

1995 ◽

Vol 53 ◽

pp. 256-257

Author(s):

J. Drucker ◽

R. Sharma ◽

J. Kouvetakis ◽

K.H.J. Weiss

Keyword(s):

Electron Beam ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Quantum Effect ◽

Line Drawing ◽

Chemical Vapor ◽

Environmental Cell ◽

Engineering Changes ◽

Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

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The relaxation of compressive biaxial strains in SOS via microtwins

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155013 ◽

1989 ◽

Vol 47 ◽

pp. 608-609

Author(s):

M. E. Twigg ◽

E. D. Richmond ◽

J. G. Pellegrino

Keyword(s):

Thin Film ◽

Chemical Vapor Deposition ◽

Molecular Beam Epitaxy ◽

Compressive Stress ◽

Vapor Deposition ◽

Partial Dislocation ◽

Molecular Beam ◽

Volume Fraction ◽

Chemical Vapor ◽

Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

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