Defect Engineering and Characterization in Oxide Surfaces using Electron Beam Irradiation

1993 ◽  
Vol 316 ◽  
Author(s):  
D. L. Doering ◽  
K. H. Siek ◽  
P. Xiong-Skiba ◽  
D. L. Carroll
Keyword(s):  
Electron Beam ◽  
Electron Emission ◽  
Electron Beam Irradiation ◽  
Defect Formation ◽  
Ion Beam ◽  
Thermionic Emission ◽  
Binding Energies ◽  
Excess Charge ◽  
Beam Irradiation ◽  
Defect Creation

ABSTRACTElectron beam irradiation at energies between 0.5 and 4 keV has been found to produce defects in oxide materials including SiO2, Al2O3 and ZrO2. These defects trap excess charge in the materials and affect their electronic and optical properties. Measurements of the thermally stimulated exoelectron emission following irradiation provides information on relative defect concentrations, defect creation mechanisms, electron trap binding energies, electron emission mechanisms and annealing properties of these materials. Electron emission during sample heating occurs via a variety of mechanisms including the thermionic emission of excess charge from defects at temperatures characteristic of each trap binding energy. By measuring relative trap concentrations as a function of beam parameters, we have identified electron beam energy thresholds for the creation of some types of defects which correlate with core level electronic transitions. Also, electron emission which occurs during defect annealing or diffusion to a surface shows the conditions for the elimination of defects. The ability to control and characterize defect formation and annihilation provides the possibility of engineering specific surface defect conditions. In addition, defect creation by electronic processes is very selective as compared with momentum transfer in ion beam damage of surfaces.

Defect Creation and Electron Trapping in Single Crystal and Sintered Alumina by Electron Beam Irradiation

1992 ◽  
Vol 279 ◽  
Author(s):  
D. L. Carroll ◽  
D. L. Doering ◽  
P. Xiong-Skiba
Keyword(s):  
Electron Beam ◽  
Single Crystal ◽  
Electron Beam Irradiation ◽  
Thermionic Emission ◽  
Charge Trapping ◽  
Binding Energies ◽  
Electron Trapping ◽  
Excess Charge ◽  
Beam Irradiation ◽  
Core Electron

ABSTRACTElectron beam irradiation of oxides produces electron trapping states which store excess charge. Thermionic emission of this charge occurs during heating with emission peak temperatures related to binding mechanisms and energies. We present thermionic emission results which show both intrinsic and beam induced trapping states in OC-Al2O3 (sapphire) and sintered alumina. Five states have been identified with thermionic emission peaks at temperatures between -50°C and 500°C. Two states are electron beam induced and occur only for electron beam energies above fixed thresholds. These thresholds appear to correlate to with the Is core electron binding energies for oxygen and aluminum. The emission peaks from the sintered material are about 10 fold greater in intensity and slightly broadened in comparison to the single crystal. This suggests that structure plays an important role in charge trapping. Emission was also extremely sensitive to sample treatments such as annealing before electron irradiation.

Defect Creation by Electron Beam Irradiation in Amorphous Silicon Nitride Films Compared with That by Light Soaking

2001 ◽  
Vol 664 ◽  
Author(s):  
Tatsuo Shimizu ◽  
Yuji Kawashima ◽  
Minoru Kumeda
Keyword(s):  
Electron Beam ◽  
Silicon Nitride ◽  
Spin Density ◽  
Electron Beam Irradiation ◽  
Dangling Bond ◽  
Beam Irradiation ◽  
Amorphous Silicon Nitride ◽  
Silicon Nitride Films ◽  
Defect Creation ◽  
G Value

ABSTRACTDefect creation by electron beam irradiation is compared with that by light soaking in a-Si1-xNx:H films. For the film with x=0.06, the ESR spin density increases by 20-keV electron beam irradiation without changes in the g-value. However, for the film with x=0.47, the ESR spin density increases with accompanying the decrease in the g-value from 2.0042 to 2.0034. The decrease in the g-value can be explained by increasing number of N atoms at the backbond site of the Si atom having the dangling bond. Light soakings does not change the g-value of the ESR signals of the films.

scholarly journals Cathodoluminescence of green fluorescent protein exhibits the redshifted spectrum and the robustness

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Keiichirou Akiba ◽  
Katsuyuki Tamehiro ◽  
Koki Matsui ◽  
Hayata Ikegami ◽  
Hiroki Minoda
Keyword(s):  
Optical Properties ◽  
Electron Beam ◽  
Electron Microscope ◽  
Green Fluorescent Protein ◽  
Electron Beam Irradiation ◽  
Fluorescent Protein ◽  
Structural Information ◽  
Ion Beam ◽  
Beam Irradiation ◽  
Green Fluorescent

Abstract Green fluorescent protein (GFP) and its variants are an essential tool for visualizing functional units in biomaterials. This is achieved by the fascinating optical properties of them. Here, we report novel optical properties of enhanced GFP (EGFP), which is one of widely used engineered variants of the wild-type GFP. We study the electron-beam-induced luminescence, which is known as cathodoluminescence (CL), using the hybrid light and transmission electron microscope. Surprisingly, even from the same specimen, we observe a completely different dependences of the fluorescence and CL on the electron beam irradiation. Since light emission is normally independent of whether an electron is excited to the upper level by light or by electron beam, this difference is quite peculiar. We conclude that the electron beam irradiation causes the local generation of a new redshifted form of EGFP and CL is preferentially emitted from it. In addition, we also find that the redshifted form is rather robust to electron bombardment. These remarkable properties can be utilized for three-dimensional reconstruction without electron staining in focused ion beam/scanning electron microscopy technology and provide significant potential for simultaneously observing the functional information specified by super-resolution CL imaging and the structural information at the molecular level obtained by electron microscope.

Reversible Tuning of the Electronic Properties of Graphene via Controlled Exposure to Electron Beam Irradiation and Annealing

2011 ◽  
Vol 1344 ◽  
Author(s):  
Desalegne Teweldebrhan ◽  
Guanxiong Liu ◽  
Alexander A. Balandin
Keyword(s):  
Electron Beam ◽  
Irradiation Dose ◽  
Carrier Mobility ◽  
Electron Beam Irradiation ◽  
Defect Formation ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Beam Irradiation ◽  
Mobility Shift ◽  
Point Increase

ABSTRACTGraphene reveals many extraordinary properties including extremely high room temperature carrier mobility and intrinsic thermal conductivity. Understanding how to controllably modify graphene’s properties is essential for its proposed applications. Here we report on a method for tuning the electrical properties of graphene via electron beam irradiation. It was observed that single-layer graphene is highly susceptible to the low-energy electron beams. We demonstrated that by controlling the irradiation dose one can change, by desired amount, the carrier mobility, shift the charge neutrality point, increase the resistance at the minimum conduction point, induce the “transport gap” and achieve current saturation in graphene. The change in graphene properties is due to defect formation on the graphene surface and in the graphene lattice. The changes are reversible by annealing until some critical irradiation dose is reached.

Preferential hole defect formation in monolayer WSe2 by electron-beam irradiation

2021 ◽  
Vol 5 (4) ◽  
Author(s):  
Donghan Shin ◽  
Gang Wang ◽  
Mengjiao Han ◽  
Zeyu Lin ◽  
Andrew O'Hara ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Defect Formation ◽  
Beam Irradiation ◽  
Hole Defect
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