Infrared-Photovoltaic Responses of Ion-Beam Synthesized β-FeSi2/n-Si Heterojunctions

1999 ◽  
Vol 607 ◽  
Author(s):  
Yoshihito Maeda ◽  
Kenji Umezawa ◽  
Kiyoshi Miyake ◽  
Kenya Ohashi
Keyword(s):  
Room Temperature ◽  
Interband Transition ◽  
Ion Beam ◽  
Photovoltaic Cells ◽  
Threshold Energy ◽  
Surface Recombination ◽  
Wavelength Region ◽  
Pronounced Increase ◽  
Surface Recombination Rate ◽  
Trap Levels

AbstractPhotoresponses of photovoltaic cells using ion-beam synthesized (IBS) polycrystalline p+-β-FeSi2/n-Si heterojunctions were examined in an infrared (IR) wavelength region. At room temperature, an evident photoresponse due to an internal photoemission from trap levels in β-FeSi2 with the threshold energy Φ=0.62 eV was observed at 0.6-0.87 eV. The pronounced increase of a photoresponse corresponding mostly to an interband transition in β-FeSi2 was observed at 0.87-1.1 eV. The maximum dominated by a surface recombination process appeared around ∼1.2 eV. The surface recombination rate of ∼104 cm/s was estimated. The quantum efficiency was ∼60 % in the 0.8-1.0 µm wavelength region and ∼14 % around the band-gap of βFeSi2.

Defects and AlSb Precipitate Nucleation in Laser Irradiated Aluminum

1981 ◽  
Vol 4 ◽  
Author(s):  
P. S. Peercy ◽  
D. M. Follstaedt ◽  
S. T. Picraux ◽  
W. R. Wampler
Keyword(s):  
Room Temperature ◽  
Laser Energy ◽  
Ion Beam ◽  
Threshold Energy ◽  
Single Pulse ◽  
Temperature Profiles ◽  
Beam Analysis ◽  
Slip Deformation ◽  
Precipitate Nucleation ◽  
Substrate Temperatures

ABSTRACTLattice defects and precipitates induced in unimplanted and Sb-implanted <110> single crystal Al by single pulse irradiation with a Q-switched ruby laser were studied using ion beam analysis and electron microscopy. The absorbed laser energy during irradiation is directly measured in these studies to allow precise numerical modeling of the melt times and temperature profiles. For unimplanted Al, slip deformation gives rise to increased channeled yields throughout the analyzed depth and occurs for energies well below the melt threshold energy of 3.5 J/cm2. Slip deformation is also observed for irradiation energies above the melt threshold energy, and melting is accompanied by a discontinuous increase in the minimum channeling yield, X min- Implanted Sb (to ∼2 at.% peak concentrations) is found to impede epitaxial regrowth and result in polycrystalline Al formation for laser energies such that the melt front is believed not to penetrate through the Sb-containing region. For deeper melt depths, a metastable alloy is formed with up to 35% of the Sb located in substitutional sites. AlSb precipitate formation in the melt was not observed for room temperature irradiations; however, randomly oriented AlSb precipitates are observed for irradiation at substrate temperatures of 100 and 200 °C These measurements yield an estimated time for nucleation of AlSb precipitates in molten Al of 5 nsec < tnuc < 25 nsec.

scholarly journals О рекомбинационных процессах в пленках CdS-PbS

2018 ◽  
Vol 52 (8) ◽  
pp. 853
Author(s):  
А.Г. Роках ◽  
М.И. Шишкин ◽  
В.С. Аткин
Keyword(s):  
Recombination Rate ◽  
Room Temperature ◽  
Surface Recombination ◽  
Active Surface ◽  
Charge Carriers ◽  
Narrow Gap ◽  
Surface Recombination Rate ◽  
Gap Phase

AbstractThe transverse and longitudinal photoconductivity, photoluminescence, and cathodoluminescence of sublimated (CdS)_0.9–(PbS)_0.1 films at room temperature and upon cooling are studied. The role of inclusions of the narrow-gap phase in the processes is shown. The films are excited over the entire active surface and pointwise (within one crystallite). The surface recombination rate and the lifetime of majority charge carriers at different generation rates and characters of excitation are estimated. A comparative table of recombination parameters of CdS and CdS–PbS films is presented.

Irradiation Cascade Threshold Energy in Gold

1970 ◽  
Vol 28 ◽  
pp. 408-409
Author(s):  
D.E. Weber ◽  
R.L. Hines
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Threshold Energy ◽  
Current Profile ◽  
Ion Energy ◽  
Weak Beam ◽  
Beam Image ◽  
Before And After ◽  
Uniform Current ◽  
Dose Levels

Xenon ions, Xe131, were used to bombard 200A thick, (100) single crystal gold film in a non-channeling direction at room temperature. The incident ion energy was In the 2-40 kev energy range. The ion beam had a uniform current profile which was monitored in two directions before and after the bombardment. The Ion dose levels were of order 1×1010/cm2.The resultant damage was viewed at room temperature in an Hitachi HU 11A electron microscope operated at lOOkev using 200 weak beam techniques. The micrographs of FIG. 1(a) and 1(b) are of the same area at different deviations. FIG. 1(a) represents the image of the damage at low deviation. The high deviation weak beam image is shown in FIG.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

scholarly journals Electrically Conductive Networks from Hybrids of Carbon Nanotubes and Graphene Created by Laser Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1875
Author(s):  
Alexander Yu. Gerasimenko ◽  
Artem V. Kuksin ◽  
Yury P. Shaman ◽  
Evgeny P. Kitsyuk ◽  
Yulia O. Fedorova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Laser Irradiation ◽  
Flexible Electronics ◽  
Threshold Energy ◽  
Wavelength Region ◽  
Hybrid Nanostructures ◽  
Graphene Sheets ◽  
Electrically Conductive ◽  
Walled Carbon Nanotubes

A technology for the formation of electrically conductive nanostructures from single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), and their hybrids with reduced graphene oxide (rGO) on Si substrate has been developed. Under the action of single pulses of laser irradiation, nanowelding of SWCNT and MWCNT nanotubes with graphene sheets was obtained. Dependences of electromagnetic wave absorption by films of short and long nanotubes with subnanometer and nanometer diameters on wavelength are calculated. It was determined from dependences that absorption maxima of various types of nanotubes are in the wavelength region of about 266 nm. It was found that contact between nanotube and graphene was formed in time up to 400 fs. Formation of networks of SWCNT/MWCNT and their hybrids with rGO at threshold energy densities of 0.3/0.5 J/cm2 is shown. With an increase in energy density above the threshold value, formation of amorphous carbon nanoinclusions on the surface of nanotubes was demonstrated. For all films, except the MWCNT film, an increase in defectiveness after laser irradiation was obtained, which is associated with appearance of C–C bonds with neighboring nanotubes or graphene sheets. CNTs played the role of bridges connecting graphene sheets. Laser-synthesized hybrid nanostructures demonstrated the highest hardness compared to pure nanotubes. Maximum hardness (52.7 GPa) was obtained for MWCNT/rGO topology. Regularity of an increase in electrical conductivity of nanostructures after laser irradiation has been established for films made of all nanomaterials. Hybrid structures of nanotubes and graphene sheets have the highest electrical conductivity compared to networks of pure nanotubes. Maximum electrical conductivity was obtained for MWCNT/rGO hybrid structure (~22.6 kS/m). Networks of nanotubes and CNT/rGO hybrids can be used to form strong electrically conductive interconnections in nanoelectronics, as well as to create components for flexible electronics and bioelectronics, including intelligent wearable devices (IWDs).

Compression of Single-Crystal Micropillars of the Γ Intermetallic Phase in the Fe-Zn System

2014 ◽  
Vol 922 ◽  
pp. 264-269 ◽  
Author(s):  
Masahiro Inomoto ◽  
Norihiko L. Okamoto ◽  
Haruyuki Inui
Keyword(s):  
Single Crystal ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Intermetallic Phase ◽  
Gamma Phase ◽  
Compression Tests ◽  
Slip Direction ◽  
Beam Method

The deformation behavior of the Γ (gamma) phase in the Fe-Zn system has been investigated via room-temperature compression tests of single-crystal micropillar specimens fabricated by the focused ion beam method. Trace analysis of slip lines indicates that {110} slip occurs for the specimens investigated in the present study. Although the slip direction has not been uniquely determined, the slip direction might be <111> in consideration of the crystal structure of the Γ phase (bcc).

scholarly journals Room temperature deposition of superconducting niobium nitride films by ion beam assisted sputtering

APL Materials ◽  
2018 ◽  
Vol 6 (7) ◽  
pp. 076107 ◽  
Author(s):  
Tomas Polakovic ◽  
Sergi Lendinez ◽  
John E. Pearson ◽  
Axel Hoffmann ◽  
Volodymyr Yefremenko ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Niobium Nitride ◽  
Temperature Deposition

AFM Study of Surface Morphology of Aluminum Nitride Thin Films

1995 ◽  
Vol 388 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura ◽  
Shigekazu Hirayama ◽  
Yuusaku Naota
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Ion Beam ◽  
Soda Lime ◽  
Silicon Single Crystal ◽  
Soda Lime Glass ◽  
Average Roughness

AbstractAluminum nitride (AlN) thin films have been synthesized by ion-beam assisted deposition method. Film deposition has been performed on the substrates of silicon single crystal, soda-lime glass and alumin A. the influence of the substrate roughness on the film roughness is studied. the substrate temperature has been kept at room temperature and 473K and the kinetic energy of the incident nitrogen ion beam and the deposition rate have been fixed to 0.5 keV and 0.07 nm/s, respectively. the microstructure of the synthesized films has been examined by X-ray diffraction (XRD) and the surface morphology has been observed by atomic force microscopy(AFM). IN the XRD patterns of films synthesized at both room temperature and 473K, the diffraction line indicating the alN (10*0) can be discerned and the broad peak composed of two lines indicating the a1N (00*2) and a1N (10*1) planes is also observed. aFM observations for 100 nm films reveal that (1) the surface of the films synthesized on the silicon single crystal and soda-lime glass substrates is uniform and smooth on the nanometer scale, (2) the average roughness of the films synthesized on the alumina substrate is similar to that of the substrate, suggesting the evaluation of the average roughness of the film itself is difficult in the case of the rough substrate, and (3) the average roughness increases with increasing the substrate temperature.

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