The Photoluminescence Enhancement and Stability of Porous Silicon by Cathodic Reduction and Acid Treatment

2014 ◽  
Vol 887-888 ◽  
pp. 458-461
Author(s):  
Chang Qing Li ◽  
Kun Wang ◽  
Pei Jia Liu ◽  
Qi Ming
Keyword(s):  
Electron Microscope ◽  
Porous Silicon ◽  
Acid Treatment ◽  
Cathodic Reduction ◽  
Luminescence Properties ◽  
Sem Images ◽  
Photoluminescence Enhancement ◽  
The Stability ◽  
Scanning Electron ◽  
Cathode Reduction

Porous silicon (PSi) was fabricated by using electrochemical anodic etching method. Then acid treatment and cathode reduction treatment were employed to improve the luminescence properties and stability of PSi material. Photoluminescence (PL) measurements and scanning electron microscope (SEM) were used to observe the luminescence properties and microstructure of samples, respectively. The results of PL measurements showed that the PL intensity and the stability of luminescence of samples after cathodic reduction and acid treatment were significantly improved. The SEM images showed that the porosity of PSi may be increased through the cathodic reduction treated.

The Energy Spectra of Secondary Electrons

2000 ◽  
Vol 6 (S2) ◽  
pp. 750-751
Author(s):  
David C Joy ◽  
David Braski
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Secondary Electron ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Energy Spectra ◽  
Yield Coefficient ◽  
Sem Images ◽  
Secondary Electrons ◽  
Scanning Electron

It has been estimated that more than 90% of all scanning electron microscope (SEM) images ever published have been obtained using secondary electrons (SE) which are defined as being those electrons emitted with energies between 0 and 50eV. The properties of these secondary electron are therefore of considerable interest and importance. However, although secondary electrons have been intensively studied since their discovery by Starke in 1901 the majority of the work has been aimed at determining the SE yield coefficient and its variation with energy for elements and compounds. The energy spectrum of secondary electrons has received far less attention although it is evident that the form of the spectrum must have an effect on the image contrast observed in the SEM because SE detectors are energy selective devices. The few studies that have been made have mostly concentrated on spectra obtained from clean samples observed under ultra-high vacuum conditions. This is understandable, because it is certain that the presence of a surface layer of contamination will change the SE spectrum to some degree or other, but it is unfortunate because all specimens in real SEMs are dirty and it is information about this situation that is required.

Thick photoresists for electroforming metallic microcomponents

2008 ◽  
Vol 222 (1) ◽  
pp. 37-42 ◽  
Author(s):  
X Wei ◽  
C-H Lee ◽  
Z Jiang ◽  
K Jiang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Current Paper ◽  
Sem Images ◽  
Advantages And Disadvantages ◽  
Uv Lithography ◽  
Electroforming Process ◽  
Electroformed Nickel ◽  
Scanning Electron

Recently, microelectroforming has been extensively applied to fabricating metallic components for sensors, actuators, and other systems. Thick photoresists are used for making micromoulds for electroforming and closely related to the quality and costs of an electroforming process. In the current paper, thick UV photoresists SU8, BPR100, and KMPR are analysed and compared in their electroforming performance of nickel microcomponents. Optimized UV lithography processes are introduced for producing micromoulds in each of the resists and scanning electron microscope (SEM) images of the moulds are presented and analysed. Then, electroformed nickel components from the micromoulds are presented. Finally, applicability of the photoresists to electroforming microcomponents is discussed. Each of the resists demonstrates advantages and disadvantages to suit different applications.

PET Depolymerization Catalyzed by Sulfates under Microwave Irradiation

2012 ◽  
Vol 550-553 ◽  
pp. 792-797 ◽  
Author(s):  
Wei Lu Zhang ◽  
Xiao Ni Shi ◽  
Xin Zhang ◽  
Chun Hua Han ◽  
Dong Zhang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microwave Irradiation ◽  
Polyethylene Terephthalate ◽  
Sem Images ◽  
Scanning Electron

Different sulfates were used as the catalysts of polyethylene terephthalate (PET) depolymerization under microwave of 250 watts, in which ZnSO4presented the best catalysis in this reaction, and the depolymerization degree (DPD) of PET was reached to 90 %. It was found that the depolymerization was occurred simultaneously on the surface and the internal parts of PET chips by the observation of scanning electron microscope (SEM) images. In addition, DPD increased with the improvement of the polarization forces of these sulfates.

scholarly journals QUALITY REINFORCEMENT OF ELECTROPLATING ZINC COATINGSELECTRODEPOSITED FROM CYANIDE FREE ALKALINE SOLUTION BY POLYAMINE 70.000 AND POLYVINYL ALCOHOL 16.000

2018 ◽  
Vol 55 (5B) ◽  
pp. 18
Author(s):  
Truong Thi Nam
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Polyvinyl Alcohol ◽  
Zinc Coating ◽  
Alkaline Solutions ◽  
Zinc Ions ◽  
Sem Images ◽  
Zinc Coatings ◽  
Scanning Electron ◽  
Good Agreement

Zinc coatings have been deposited electrochemically from cyanine free alkaline solutions containing zinc ions with the presence of polyamine 70.000 and polyvinyl alcohol at different contents. The scanning electron microscope (SEM) images showed that the size of zinc grains decreased with the presence of polyamine 70.000 and polyvinyl alcohol with smoother surface of zinc coating. The polarization measurements also revealed that the coatings with the presence of polyamine or polyvinyl alcohol possessed higher value of polarity degree. This result is in good agreement with the result obtained from SEM images.

IVEM and SEM images of whole cells cultured on EHS matrix (Matrigel)

1991 ◽  
Vol 49 ◽  
pp. 186-187
Author(s):  
Nancy R. Smith ◽  
Stephen Benson ◽  
Carolyn Larabell
Keyword(s):  
Electron Microscope ◽  
Model System ◽  
Lung Fibroblasts ◽  
Rat Lung ◽  
Sem Images ◽  
Whole Cells ◽  
Voltage Electron ◽  
Matrix Interactions ◽  
Scanning Electron

To investigate the interactions of cells with the extracellular matrix (ECM), rat lung fibroblasts (RLF) were cultured on an ECM extracted from EHS sarcoma to serve as an in vitro morphogenic model system. Surface features of RLF/EHS matrix interactions were viewed using the scanning electron microscope (SEM) and the intermediate voltage electron microscope (IVEM).For SEM, RLF were plated on EHS coated 13 mm glass coverslips at a density of 1 X 104/cm2. Coverslips were coated by spreading 25 μl of chilled EHS matrix (15 mg/ml) on the coverslip and incubating at 37° for 60 min. For IVEM, formvar coated gold grids were submerged in EHS matrix prior to polymerization. Controls consisted of cells grown on glass or gold grids minus ECM.

Performance enhancement of Scanning Electron Microscope using a Deep Convolutional Neural Network

2022 ◽  
Author(s):  
Suresh Panchal ◽  
Unnikrishnan Gopinathan ◽  
Suwarna Datar
Keyword(s):  
Neural Network ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Convolutional Neural Network ◽  
Performance Enhancement ◽  
Deep Convolutional Neural Network ◽  
Sem Images ◽  
Scan Rate ◽  
Charging Effect ◽  
Scanning Electron

Abstract We report noise reduction and image enhancement in Scanning Electron Microscope (SEM) imaging while maintaining a Fast-Scan rate during imaging, using a Deep Convolutional Neural Network (D-CNN). SEM images of non-conducting samples without conducting coating always suffer from charging phenomenon, giving rise to SEM images with low contrast or anomalous contrast and permanent damage to the sample. One of the ways to avoid this effect is to use Fast-Scan mode, which suppresses the charging effect fairly well. Unfortunately, this also introduces noise and gives blurred images. The D-CNN has been used to predict relatively noise-free images as obtained from a Slow-Scan from a noisy, Fast-Scan image. The predicted images from D-CNN have the sharpness of images obtained from a Slow-Scan rate while reducing the charging effect due to images obtained from Fast-Scan rates. We show that using the present method, and it is possible to increase the scanning rate by a factor of about seven with an output of image quality comparable to that of the Slow-Scan mode. We present experimental results in support of the proposed method.

STRUCTURAL AND OPTICAL FEATURES OF POROUS SILICON PREPARED BY ELECTROCHEMICAL ANODIC ETCHING

2009 ◽  
Vol 16 (01) ◽  
pp. 93-97 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
F. K. YAM ◽  
H. ABU HASSAN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Porous Silicon ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Raman Peak ◽  
Sem Images ◽  
Anodic Etching ◽  
Etching Duration ◽  
Scanning Electron

Porous silicon (PS) samples were prepared by electrochemical anodic etching of n-type (111) silicon wafers in HF solution. The structural, optical, and chemical features of the PS were investigated in terms of different etching durations. The porous samples were investigated by scanning electron microscopy (SEM), photoluminescence (PL), and Raman scattering. SEM images indicated that the pores increased with the etching duration; however, the etching duration has significant effect on the shape of the pores. PL measurements revealed that the porosity-induced PL intensity enhancement was only observed in the porous samples. Raman spectra showed shifting of PS Raman peak to lower frequency relative to non-porous silicon Raman peak.

Single Phase Pyrite Synthesized via Hydrothermal Method

2013 ◽  
Vol 562-565 ◽  
pp. 136-140 ◽  
Author(s):  
Zhao Tang Yang ◽  
Xiao Jiang Liu ◽  
Jing Song Liu ◽  
Xiu Li Feng
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hydrothermal Method ◽  
Single Phase ◽  
Sem Images ◽  
X Ray ◽  
Decreasing Ph ◽  
Size And Morphology ◽  
Ph Range ◽  
Scanning Electron

Single phase pyrite has been successfully prepared via the reaction of FeSO4·7H2O, S and Na2S·9H2O using hydrothermal method. The X-ray powder diffraction measurements confirm the formation of iron disulfides in the pH range of 1-12. Marcasite is formed at pH<4, the marcasite contents in the final products increasing with decreasing pH; when the pH is higher than 4, the final product is single phase pyrite. Scanning electron microscope (SEM) images reveal that both the pH and temperatures have significant effects on the size and morphology of final products. Pyrite micro-nanocubes of 200-400nm in length were synthesized at pH=9. Detailed information of the experimental results are analyzed in the results and discussion part.

Alloperla clarki sp. nov. (Plecoptera: Chloroperlidae), a new species from the eastern Nearctic with discussion of a new species group

Zootaxa ◽  
2019 ◽  
Vol 4624 (2) ◽  
pp. 241-255
Author(s):  
SCOTT A. GRUBBS ◽  
RICHARD W. BAUMANN
Keyword(s):  
Electron Microscope ◽  
New Species ◽  
Scanning Electron Microscope ◽  
Adult Male ◽  
Appalachian Mountains ◽  
Geographic Area ◽  
Species Group ◽  
Sem Images ◽  
A New Species ◽  
Scanning Electron

Alloperla Banks, 1906 (Plecoptera: Chloroperlidae) is a speciose genus of spring- and summer-emergent stoneflies known from the Oriental, eastern Palearctic, and Nearctic realms. Over 50 species are currently recognized. Alloperla clarki sp. nov. is described herein from the adult male stage from a small geographic area in the Appalachian Mountains in Virginia and West Virginia, USA. Diagnostic characters are presented with scanning electron microscope (SEM) photomicrographs. Alloperla clarki sp. nov. most closely resembles A. biserrata Nelson & Kondratieff, 1980, A. nanina Banks, 1911, and A. stipitata Surdick, 2004. These four species share similar characteristics of the male epiproct and appear to comprise a species group. The Alloperla nanina Group is formally proposed. Comparative SEM images are also provided for A. biserrata, A. nanina, and A. stipitata to assist with differentiating between these four species. 

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