scholarly journals Formation and Properties of Porous GaAs

1996 ◽  
Vol 431 ◽  
Author(s):  
P. Schmuki ◽  
D. J. Lockwood ◽  
J. W. Fraser ◽  
M. J. Graham ◽  
H. S. Isaacs
Keyword(s):  
Porous Structure ◽  
Pore Formation ◽  
Surface Defects ◽  
Light Emission ◽  
Porous Structures ◽  
Onset Potential ◽  
Porous Gaas ◽  
Anion Uptake ◽  
Visible Light Emission ◽  
Good Agreement

AbstractPorous structures on n-type GaAs (100) can be grown electrochemically in chloridecontaining solutions. Crystallographic etching of the sample is a precursor stage of the attack. Polarization curves reveal the existence of a critical onset potential for pore formation (PFP). The PFP is strongly dependent on the doping level of the sample and the presence of surface defects. Good agreement between the PFP and the breakdown voltage of the space charge layer is found. Surface analytical investigations by EDX, AES and XPS show that the porous structure consists mainly of GaAs and that anion uptake in the structure can only be observed after attack has been initiated. Photoluminescence measurements reveal – under certain conditions – visible light emission from the porous structure.

Pore Formation and Propagation Mechanism in Porus Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
V. Lehmann ◽  
H. Cerva ◽  
U. Gosele
Keyword(s):  
Porous Structure ◽  
Space Charge ◽  
Space Charge Region ◽  
Formation Process ◽  
Quantum Confinement ◽  
Pore Formation ◽  
Propagation Mechanism ◽  
Porous Structures

ABSTRACTThis paper presents a model of the microporous silicon formation process which is based on hole depletion due to quantum confinement in the porous structure. This model is compared with the formation of larger porous structures (meso-, macroporous) where hole depletion is generated by a space charge region.

Scanning luminescence x-ray microscopy: Progress toward selective staining using microspheres

1994 ◽  
Vol 52 ◽  
pp. 74-75
Author(s):  
C. Jacobsen ◽  
J. Fu ◽  
S. Mayer ◽  
Y. Wang ◽  
S. Williams
Keyword(s):  
Visible Light ◽  
Active Sites ◽  
Light Emission ◽  
Chinese Hamster ◽  
Polystyrene Spheres ◽  
Good Resistance ◽  
X Ray ◽  
Selective Staining ◽  
Visible Light Emission ◽  
Specific Labelling

In scanning luminescence x-ray microscopy (SLXM), a high resolution x-ray probe is used to excite visible light emission (see Figs. 1 and 2). The technique has been developed with a goal of localizing dye-tagged biochemically active sites and structures at 50 nm resolution in thick, hydrated biological specimens. Following our initial efforts, Moronne et al. have begun to develop probes based on biotinylated terbium; we report here our progress towards using microspheres for tagging.Our initial experiments with microspheres were based on commercially-available carboxyl latex spheres which emitted ~ 5 visible light photons per x-ray absorbed, and which showed good resistance to bleaching under x-ray irradiation. Other work (such as that by Guo et al.) has shown that such spheres can be used for a variety of specific labelling applications. Our first efforts have been aimed at labelling ƒ actin in Chinese hamster ovarian (CHO) cells. By using a detergent/fixative protocol to load spheres into cells with permeabilized membranes and preserved morphology, we have succeeded in using commercial dye-loaded, spreptavidin-coated 0.03μm polystyrene spheres linked to biotin phalloidon to label f actin (see Fig. 3).

Novel Process for Visible Light Emission from Si Prepared by Ion Irradiation

1992 ◽  
Vol 31 (Part 2, No. 5A) ◽  
pp. L560-L563 ◽  
Author(s):  
Yukinori Ochiai ◽  
Norio Ookubo ◽  
Heiji Watanabe ◽  
Shinji Matsui ◽  
Yasunori Mochizuki ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Emission ◽  
Ion Irradiation ◽  
Visible Light Emission

Predicting the surface waviness of sheet moulding compound parts by simulating process-induced thermal stresses

2011 ◽  
Vol 31 (8-9) ◽  
Author(s):  
Walter Michaeli ◽  
Christoph Kremer
Keyword(s):  
Thermal Stresses ◽  
Surface Defects ◽  
Computation Method ◽  
Surface Waviness ◽  
Curing Reaction ◽  
Calculated Stress ◽  
Moulding Compound ◽  
Different Types ◽  
Sheet Moulding Compound ◽  
Good Agreement

Abstract This paper describes an opportunity to compute the surface waviness of compression moulded sheet moulding compound (SMC) parts by simulating residual stresses. First, different types of surface defects occurring on SMC parts are discussed. A method for calculating the surface waviness of the compression moulded part is presented, which combines the simulation of the production process and the structural computation. Modelling of the curing reaction and the development of mechanical properties are discussed and implemented. The potential of the computation method is shown for an automotive fender made of SMC. The results state that the curing reaction of SMC can be well described using the approach of Ng and Manas-Zloczower. The position of the measured waviness on the examined fender is in good agreement with the calculated stress distribution.

Impact ionization, recombination, and visible light emission in AlGaAs/GaAs high electron mobility transistorsa)

1991 ◽  
Vol 70 (1) ◽  
pp. 529-531 ◽  
Author(s):  
Enrico Zanoni ◽  
Alessandro Paccagnella ◽  
Pietro Pisoni ◽  
Paolo Telaroli ◽  
Carlo Tedesco ◽  
...  
Keyword(s):  
Visible Light ◽  
Electron Mobility ◽  
Impact Ionization ◽  
Light Emission ◽  
High Electron ◽  
High Electron Mobility ◽  
Visible Light Emission

scholarly journals Tailorable, visible light emission from silicon nanocrystals

1999 ◽  
Vol 74 (21) ◽  
pp. 3164-3166 ◽  
Author(s):  
J. P. Wilcoxon ◽  
G. A. Samara
Keyword(s):  
Visible Light ◽  
Silicon Nanocrystals ◽  
Light Emission ◽  
Visible Light Emission

Prediction of Defects in Multistage Cold Forging by Using Finite Element Method

2014 ◽  
Vol 622-623 ◽  
pp. 659-663 ◽  
Author(s):  
Fabio Bassan ◽  
Paolo Ferro ◽  
Franco Bonollo
Keyword(s):  
Radial Flow ◽  
Surface Defects ◽  
Plastic Instability ◽  
Cold Forging ◽  
Formation Mechanisms ◽  
Fe Model ◽  
Pipe Fitting ◽  
Tooling Design ◽  
Simulated Flow ◽  
Good Agreement

In this work, the formation mechanisms of surface defects in multistage cold forging of axisymmetrical parts have been studied through FEM simulations. As case history, the industrial production of an heating pipe fitting by cold forging has been analyzed. Based on simulated flow behaviour of material, several types of surface defects are identified and attributed to plastic instability of the work-material, inappropriate axial/radial flow ratio, excessive forming-pressure and uncorrect tooling design. The results of the FE model are finally compared with those obtained from real forging process and good agreement is observed.

scholarly journals Visible light emission from semiconducting polymer diodes

1991 ◽  
Vol 58 (18) ◽  
pp. 1982-1984 ◽  
Author(s):  
D. Braun ◽  
A. J. Heeger
Keyword(s):  
Visible Light ◽  
Light Emission ◽  
Semiconducting Polymer ◽  
Visible Light Emission

scholarly journals Winter-jujube-derived carbon with self-doped heteroatoms and a hierarchically porous structure for high-performance supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43356-43365 ◽  
Author(s):  
Yuanyuan Li ◽  
Kaiwen Zheng ◽  
Sayyed Asim Ali Shah ◽  
Yizhou Huang ◽  
Yazhou Tian ◽  
...  
Keyword(s):  
Porous Structure ◽  
High Performance ◽  
Porous Structures ◽  
Hierarchically Porous ◽  
Hierarchically Porous Structure

The synthesized JC samples possessed abundant self-doped heteroatoms and hierarchically porous structures (the co-existence of micro-, meso-, and macropores).

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