Carrier-trapping induced reconstruction of partial-dislocation cores responsible for light-illumination controlled plasticity in an inorganic semiconductor

2020 ◽  
Vol 195 ◽  
pp. 645-653 ◽  
Author(s):  
Katsuyuki Matsunaga ◽  
Sena Hoshino ◽  
Masaya Ukita ◽  
Yu Oshima ◽  
Tatsuya Yokoi ◽  
...  
Keyword(s):  
Partial Dislocation ◽  
Light Illumination ◽  
Carrier Trapping ◽  
Inorganic Semiconductor

Direct Observation of Carrier Trapping Processes on Fe Impurities in mc-Si Solar Cells

2013 ◽  
Vol 205-206 ◽  
pp. 40-46 ◽  
Author(s):  
Yutaka Yoshida ◽  
Yoshinori Tsukamoto ◽  
Masahiro Ichino ◽  
Kiyotaka Tanaka
Keyword(s):  
Solar Cells ◽  
Cross Sections ◽  
Light Illumination ◽  
Carrier Trapping ◽  
Si Solar Cells ◽  
Solute Atoms ◽  
Dynamical Charge ◽  
Trapping Process ◽  
Fe Implantation ◽  
Fe Impurities

n-situ Mössbauer studies on 57Fe solute atoms in Si solar cells are performed: (1) GeV-57Mn/57Fe implantation into Si solar cells, (2) 57Fe diffused n-type Si under light illumination; (3) 57Fe diffused solar cells under applying external voltages. The carrier trapping cross sections for the interstitial components with different charge states, Fei+ and Fei2+, can be successfully obtained by evaluating the dynamical charge fluctuations within a time scale of 100ns between Fei+ and Fei2+ which appear in the Mössbauer spectra of 57Fe doped mc-Si solar cells. We further measure the distributions of Fei+ and Fei2+ by a Mössbauer Microscope, which we have been developing. The present results provide us a possibility to clarify the carrier trapping process on an atomistic scale directly on the Fe impurities in Si-solar cells.

Low-light-level three-dimensional video microscope with long working distance objective lenses

1994 ◽  
Vol 52 ◽  
pp. 226-227
Author(s):  
W. Lin ◽  
J. Gregorio ◽  
T.J. Holmes ◽  
D. H. Szarowski ◽  
J.N. Turner
Keyword(s):  
Three Dimensional ◽  
Light Level ◽  
Stereo Pair ◽  
Light Illumination ◽  
Initial Image ◽  
Low Light ◽  
Image Recording ◽  
Depth Discrimination ◽  
Video Microscope ◽  
Working Distance

A low-light level video microscope with long working distance objective lenses has been built as part of our integrated three-dimensional (3-D) light microscopy workstation (Fig. 1). It allows the observation of living specimens under sufficiently low light illumination that no significant photobleaching or alternation of specimen physiology is produced. The improved image quality, depth discrimination and 3-D reconstruction provides a versatile intermediate resolution system that replaces the commonly used dissection microscope for initial image recording and positioning of microelectrodes for neurobiology. A 3-D image is displayed on-line to guide the execution of complex experiments. An image composed of 40 optical sections requires 7 minutes to process and display a stereo pair.The low-light level video microscope utilizes long working distance objective lenses from Mitutoyo (10X, 0.28NA, 37 mm working distance; 20X, 0.42NA, 20 mm working distance; 50X, 0.42NA, 20 mm working distance). They provide enough working distance to allow the placement of microelectrodes in the specimen.

The relaxation of compressive biaxial strains in SOS via microtwins

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.

Effect of Illumination on Organic Polymer Thin-Film Transistors

2003 ◽  
Vol 771 ◽  
Author(s):  
Michael C. Hamilton ◽  
Sandrine Martin ◽  
Jerzy Kanicki
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Drain Current ◽  
Charge Carriers ◽  
Electrical Performance ◽  
Organic Polymer ◽  
Light Illumination ◽  
Polymer Thin Film ◽  
Channel Region ◽  
White Light Illumination

AbstractWe have investigated the effects of white-light illumination on the electrical performance of organic polymer thin-film transistors (OP-TFTs). The OFF-state drain current is significantly increased, while the drain current in the strong accumulation regime is relatively unaffected. At the same time, the threshold voltage is decreased and the subthreshold slope is increased, while the field-effect mobility of the charge carriers is not affected. The observed effects are explained in terms of the photogeneration of free charge carriers in the channel region due to the absorbed photons.

Natural Killer Cell Inspired AIE Nanoterminator for Blood-Brain-Barrier Crossing via Tight-Junction Modulation and NIR-II Gliomas Theranostics

2020 ◽  
Author(s):  
Guanjun Deng ◽  
Xinghua Peng ◽  
Zhihong Sun ◽  
Wei Zheng ◽  
Jia Yu ◽  
...  
Keyword(s):  
Natural Killer Cell ◽  
Natural Killer ◽  
Intracellular Signaling ◽  
Soft Matter ◽  
Tumor Imaging ◽  
Nk Cell ◽  
Killer Cell ◽  
Light Illumination ◽  
Blood Brain ◽  
Intracellular Signaling Cascade

Nature has always inspired robotic designs and concepts. It is conceivable that biomimic nanorobots will soon play a prominent role in medicine. In this paper, we developed a natural killer cell-mimic AIE nanoterminator (NK@AIEdots) by coating natural kill cell membrane on the AIE-active polymeric endoskeleton, PBPTV, a highly bright NIR-II AIE-active conjugated polymer. Owning to the AIE and soft-matter characteristics of PBPTV, as-prepared nanoterminator maintained the superior NIR-II brightness (quantum yield ~8%) and good biocompatibility. Besides, they could serve as tight junctions (TJs) modulator to trigger an intracellular signaling cascade, causing TJs disruption and actin cytoskeleton reorganization to form intercellular “green channel” to help themselves crossing Blood-Brain Barriers (BBB) silently. Furthermore, they could initiatively accumulate to glioblastoma cells in the complex brain matrix for high-contrast and through-skull tumor imaging. The tumor growth was also greatly inhibited by these nanoterminator under the NIR light illumination. As far as we known, The QY of PBPTV is the highest among the existing NIR-II luminescent conjugated polymers. Besides, the NK-cell biomimetic nanorobots will open new avenue for BBB-crossing delivery.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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