Ga-vacancy activation under low energy electron irradiation in GaN-based materials

2012 ◽  
Vol 1432 ◽  
Author(s):  
Henri Nykänen ◽  
Sami Suihkonen ◽  
Lucasz Kilanski ◽  
Markku Sopanen ◽  
Filip Tuomisto
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Vacancy Concentration ◽  
Positron Annihilation Spectroscopy ◽  
Low Energy ◽  
Energy Electron ◽  
Beam Irradiation ◽  
Organic Vapor ◽  
Metal Organic ◽  
Low Energy Electron

ABSTRACTWe present results on optical degradation of gallium nitride based materials under low energy electron beam irradiation (LEEBI). GaN thin film and GaN/InGaN quantum well samples, grown by metal-organic vapor phase epitaxy (MOVPE), were exposed to a tightly focused (ø = 2 nm, J = 0-130 kA/cm2), rapidly scanning electron beam (e-beam) with energy of 5-20 keV and dose of 0-500 μC/cm2. The irradiation severely reduced the band-to-band photoluminescence of the exposed sample areas. Performing positron annihilation spectroscopy measurements on the irradiated films revealed an important increase of Ga-vacancy concentration as a function of the irradiation dose. Based on the measurements we propose that in-grown passive VGa-Hn complexes are present in MOVPE grown GaN (and its alloys), and are activated by LEEBI.

scholarly journals Dose-rate effect of low-energy electron beam irradiation on bacterial content in chilled turkey

2021 ◽  
Vol 640 (3) ◽  
pp. 032006
Author(s):  
U A Bliznyuk ◽  
P Yu Borchegovskaya ◽  
A P Chernyaev ◽  
V S Ipatova ◽  
V A Leontiev ◽  
...  
Keyword(s):  
Electron Beam ◽  
Dose Rate ◽  
Electron Beam Irradiation ◽  
Rate Effect ◽  
Low Energy ◽  
Energy Electron ◽  
Beam Irradiation ◽  
Low Energy Electron ◽  
Bacterial Content ◽  
Dose Rate Effect

Influence of low-energy electron beam irradiation on defects in activated Mg-doped GaN

2002 ◽  
Vol 744 ◽  
Author(s):  
O. Gelhausen ◽  
M. R. Phillips ◽  
H. N. Klein ◽  
E. M. Goldys
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Low Energy ◽  
Energy Electron ◽  
Beam Irradiation ◽  
Hydrogen Atoms ◽  
Acceptor Pair ◽  
Low Energy Electron ◽  
The Impact ◽  
Mg Doped

ABSTRACTCL spectroscopy studies at varying temperatures and excitation power densities as well as depth-resolved CL imaging were conducted to investigate the impact of low energy electron beam irradiation (LEEBI) on native defects and residual impurities in metal-organic vapor phase epitaxy (MOVPE) grown Mg-doped p-type GaN. Due to the dissociation of (Mg-H)0 complexes, LEEBI significantly increases the (e,Mg0) emission (3.26 eV) at 300 K and substantially decreases the H-Mg donor-acceptor-pair (DAP) emission (3.27 eV) at 80 K. In-plane and depth-resolved CL imaging indicates that hydrogen dissociation results from electron-hole recombination at H-defect complexes rather than heating by the electron beam. The dissociated hydrogen atoms associate with nitrogen vacancies, forming a deeper donor, i.e. a (H-VN) complex. The corresponding deeper DAP emission with Mg centered at 3.1 eV is clearly observed between 160 and 220 K. Moreover, a broad yellow luminescence (YL) band centered at 2.2 eV is observed in MOVPE-grown Mg-doped GaN after LEEBI-treatment. It is suggested that a combination of LEEBI-induced Fermi-level downshift due to Mg-acceptor activation and simultaneous dissociation of gallium vacancy-impurity complexes, i.e. (VGa-H), is responsible for the observed YL.

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