ESR and LESR Studies in CVD Diamond

1996 ◽  
Vol 423 ◽  
Author(s):  
C. F. O. Graeff ◽  
E. Rohrer ◽  
C. E. Nebel ◽  
M. Stutzmann ◽  
H. GUttler ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Room Temperature ◽  
Defect Density ◽  
Uv Light ◽  
Cvd Diamond ◽  
Central Line ◽  
Dark Conductivity ◽  
Defect Line ◽  
Spin Resonance ◽  
Related Defect

AbstractCVD diamond films with nitrogen content varying from 10 ppm to 132 ppm have been studied by electron spin resonance (ESR), light-induced ESR (LESR) as well as spin-dependent conductivity (SDC). Two characteristic signals have been observed. A carbon-related defect line with g = 2.0029 ± 0.0002 and width 4 ± 1 G, is observed in ESR, LESR and SDC. The intensity of this line measured by ESR increases linearly with nitrogen content. For low-defect-density samples, or after illuminating the high-defect-density samples with UV light, a second signal is observed both in ESR and LESR, but not in SDC, with a central line at g = 2.0024 ± 0.001 and width 0.2 ± 0.1 G and related hyperfine satellites ≈30 G away from the central line. This line is assigned to isolated substitutional nitrogen, the so-called P1 center. The density of N-related paramagnetic states is strongly affected by illumination and heat treatments. Spin-dependent conductivity measurements show that the dark conductivity at room temperature in CVD-diamond is dominated by hopping at the g = 2.0029 defects.

Light Induced Effects in A-Si:H Films Alloyed with Sulfur

1997 ◽  
Vol 467 ◽  
Author(s):  
Jong-Hwan Yoon ◽  
P. C. Taylor ◽  
Baojie Yan ◽  
Czang-Ho Lee
Keyword(s):  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Dark Conductivity ◽  
Gas Mixture ◽  
Small Decrease ◽  
Illumination Time ◽  
Spin Resonance ◽  
Photo Conductivity ◽  
Order Of Magnitude ◽  
Hydrogenated Amorphous

ABSTRACTLight-induced effects are studied in hydrogenated amorphous silicon-sulfur alloys (a-SiSx:H) and compared to those that exist in a-Si:H. The a-SiSx:H films were grown by decomposition of pre-mixtures of SiH4 and H2 S. The light-induced effects were monitored using electrical (dark conductivity and photoconductivity, including the constant photocurrent method [CPM]) and optical (photoluminescence) measurements and electron spin resonance. It is found that sulfur alloying results in a significant reduction in the degradation in the dark- and photo-conductivity. For ana-SiSx:H film grown with a gas mixture of H2 S/SiH4= 0.02, there is an increase of over an order of magnitude in the dark conductivity and a small decrease in the photoconductivity after 50 hours of light soaking. The subgap deep defect density as measured by CPM increases with illumination time, following a stretched exponential to saturation. The saturated defect density is an order of magnitude higher than that observed in the annealed state.

Inert Gas Dilution and Ion Bombardment Effects in Room Temperature (35°C) Plasma Deposition of a-Si:H

1996 ◽  
Vol 420 ◽  
Author(s):  
Easwar Srinivasan ◽  
Daniel A. Lloyd ◽  
Ming Fang ◽  
Gregory N. Parsons
Keyword(s):  
Vapor Deposition ◽  
Parallel Plate ◽  
Room Temperature ◽  
Defect Density ◽  
Plasma Deposition ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Inert Gas ◽  
High Defect Density ◽  
Gas Dilution

AbstractPlasma enhanced chemical vapor deposition (PECVD) of a-Si:H with silane or silane and hydrogen at temperatures lower than 200°C commonly results in films with significant dihydride bonding and a high defect density. In this paper, we demonstrate the formation of monohydride dominant a-Si:H films using rf parallel plate PECVD at 35°C at deposition rates greater than 100 Å/min. In the as-deposited state, these films have low dark conductivity (∼10−9 S/cm) and low photoconductivity. Annealing the films at 150°C caused the monohydride dominant films to show photo to dark conductivity ratio near 105. Our results also indicate that an increase in monohydride fraction is not linked with a decrease in deposition rate.

Electron spin resonance of palladium-related defect in silicon

2009 ◽  
Vol 404 (23-24) ◽  
pp. 4586-4589
Author(s):  
T. Ishiyama ◽  
S. Kimura ◽  
Y. Kamiura ◽  
Y. Yamashita
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Spin Resonance ◽  
Related Defect

Burn-In Acceleration Considerations in 130nm and 90nm Products

2005 ◽  
Author(s):  
Nobuyuki Wakai ◽  
Yuji Kobira ◽  
Takashi Setoya ◽  
Tamotsu Oishi ◽  
Shinichi Yamasaki
Keyword(s):  
Failure Analysis ◽  
Shape Parameter ◽  
Defect Density ◽  
Failure Mechanisms ◽  
Effective Procedure ◽  
Time Period ◽  
Related Defect ◽  
The Relationship

Abstract An effective procedure to determine the Burn-In acceleration factors for 130nm and 90 nm processes are discussed in this paper. The relationship among yield, defect density, and reliability, is well known and well documented for defect mechanisms. In particular, it is important to determine the suitable acceleration factors for temperature and voltage to estimate the exact Burn- In conditions needed to screen these defects. The approach in this paper is found to be useful for recent Cu-processes which are difficult to control from a defectivity standpoint. Performing an evaluation with test vehicles of 130nm and 90nm technology, the following acceleration factors were obtained, Ea>0.9ev and β (Beta)>-5.85. In addition, it was determined that a lower defect density gave a lower Weibull shape parameter. As a result of failure analysis, it is found that the main failures in these technologies were caused by particles, and their Weibull shape parameter “m” was changed depending of the related defect density. These factors can be applied for an immature time period where the process and products have failure mechanisms dominated by defects. Thus, an effective Burn-In is possible with classification from the standpoint of defect density, even from a period of technology immaturity.

scholarly journals Force detection of high-frequency electron spin resonance near room temperature using high-power millimeter-wave source gyrotron

2021 ◽  
Vol 118 (2) ◽  
pp. 022407
Author(s):  
Hideyuki Takahashi ◽  
Yuya Ishikawa ◽  
Tsubasa Okamoto ◽  
Daiki Hachiya ◽  
Kazuki Dono ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Millimeter Wave ◽  
Electron Spin ◽  
High Power ◽  
High Frequency ◽  
Room Temperature ◽  
Force Detection ◽  
Wave Source ◽  
Spin Resonance ◽  
Millimeter Wave Source

scholarly journals Zirconium-Doped Chromium IV Oxide Nanocomposites: Synthesis, Characterization, and Photocatalysis towards the Degradation of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Zahir Muhammad ◽  
Farman Ali ◽  
Muhammad Sajjad ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Solid State ◽  
Room Temperature ◽  
Organic Dyes ◽  
Uv Light ◽  
Heterogeneous Photocatalysis ◽  
Ft Ir ◽  
Complete Mineralization

Degradation of organic dyes and their byproducts by heterogeneous photocatalysts is an essential process, as these dyes can be potentially discharged in wastewater and threaten aquatic and xerophyte life. Therefore, their complete mineralization into nontoxic components (water and salt) is necessary through the process of heterogeneous photocatalysis. In this study, Zr/CrO2 (Zirconium-doped chromium IV oxide) nanocomposite-based photocatalysts with different compositions (1, 3, 5, 7 & 9 wt.%) were prepared by an environmentally friendly, solid-state reaction at room temperature. The as-prepared samples were calcined under air at 450 °C in a furnace for a specific period of time. The synthesis of Zr/CrO2 photocatalysts was confirmed by various techniques, including XRD, SEM, EDX, FT-IR, UV-Vis, and BET. The photocatalytic properties of all samples were tested towards the degradation of methylene blue and methyl orange organic dyes under UV light. The results revealed a concentration-dependent photocatalytic activity of photocatalysts, which increased the amount of dopant (up to 5 wt.%). However, the degradation efficiency of the catalysts decreased upon further increasing the amount of dopant due to the recombination of holes and photoexcited electrons.

Photocatalytic Activity of Fe-Doped ZnO/Montmorillonite Nanocomposite for Degradation of Malachite Green

2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Photocatalytic Activity ◽  
Malachite Green ◽  
Organic Dyes ◽  
Uv Light ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Doped Zno ◽  
Co Precipitation

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

UV-Light-Induced Dehydrogenative N-Acylation of Amines with 2-Nitrobenzaldehydes to Give 2-Aminobenzamides

Synthesis ◽  
2022 ◽  
Author(s):  
Dishu Zeng ◽  
Tianbao Yang ◽  
Niu Tang ◽  
Wei Deng ◽  
Jiannan Xiang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Building Block ◽  
Room Temperature ◽  
Uv Light ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
Plausible Mechanism ◽  
High Yields

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.

High Temperature High Current Gain IC Compatible 4H-SiC Phototransistor

2019 ◽  
Vol 963 ◽  
pp. 832-836 ◽  
Author(s):  
Shuo Ben Hou ◽  
Per Erik Hellström ◽  
Carl Mikael Zetterling ◽  
Mikael Östling
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Room Temperature ◽  
Uv Light ◽  
Optical Power ◽  
Current Gain ◽  
High Current ◽  
Promising Candidate ◽  
Forward Current ◽  
On Chip

This paper presents our in-house fabricated 4H-SiC n-p-n phototransistors. The wafer mapping of the phototransistor on two wafers shows a mean maximum forward current gain (βFmax) of 100 at 25 °C. The phototransistor with the highest βFmax of 113 has been characterized from room temperature to 500 °C. βFmax drops to 51 at 400 °C and remains the same at 500 °C. The photocurrent gain of the phototransistor is 3.9 at 25 °C and increases to 14 at 500 °C under the 365 nm UV light with the optical power of 0.31 mW. The processing of the phototransistor is same to our 4H-SiC-based bipolar integrated circuits, so it is a promising candidate for 4H-SiC opto-electronics on-chip integration.

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