scholarly journals Absorption and photoconductivity spectra of amorphous multilayer structures

2020 ◽  
Vol 11 ◽  
pp. 1757-1763
Author(s):  
Oxana Iaseniuc ◽  
Mihail Iovu
Keyword(s):  
Complex Structure ◽  
Single Layer ◽  
Negative Polarity ◽  
Amorphous Layer ◽  
Experimental Results ◽  
Multilayer Structures ◽  
Metal Electrodes ◽  
Layer Structures ◽  
Work Functions ◽  
Photocurrent Spectra

The experimental results regarding optical absorption and steady-state photoconductivity of amorphous single-layer structures (Al–As0.40S0.30Se0.30–Al, Al–Ge0.09As0.09Se0.82–Al, and Al–Ge0.30As0.04S0.66–Al) and of an amorphous heterostructure (Al–As0.40S0.30Se0.30/Ge0.09As0.09Se0.82/Ge0.30As0.04S0.66–Al) at different values of the voltage, with positive or negative polarity, applied to the illuminated top Al electrode are presented and discussed. The complex structure of the photocurrent spectra is attributed to the different values of the optical bandgap of the involved amorphous layers (E g ≈ 2.0 eV for As0.40S0.30Se0.30 and Ge0.09As0.09Se0.82 and E g ≈ 3.0 eV for Ge0.30As0.04S0.66). The obtained experimental results are discussed taking into account the light absorption depending on the nature and the thickness of each amorphous layer, on the wavelength, and on contact phenomena at the interfaces between different layers and between the amorphous layers and the metal electrodes with different work functions.

Comparison of Electromigration Induced Resistance Changes in Multilayer Al-Si/Ti and Al-Si/Ta Interconnects

1986 ◽  
Vol 71 ◽  
Author(s):  
M. Finetti ◽  
I. Suni ◽  
G. Desanti ◽  
L. Bacci ◽  
C. Caprile
Keyword(s):  
Induced Resistance ◽  
Single Layer ◽  
Multilayer Structures ◽  
Resistance Analysis ◽  
Temperature Ramp

AbstractWe have applied a temperature-ramp resistance analysis to investigate electromigration effects in unpassivated Al-Si/Ta multilayer structures. The results are compared to the behaviour previously observed in Al-Si/Ti interconnects. For comparison, single layer Al-Si metallizations were also studied.

MBE Growth and Characterization of SxGe1−x Multilayer Structures on Si (100) for Use as a Substrate for GaAs Heteroepitaxy

1991 ◽  
Vol 220 ◽  
Author(s):  
J. B. Posthill ◽  
D. P. Malta ◽  
R. Venkatasubramanian ◽  
P. R. Sharps ◽  
M. L. Timmons ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Lattice Mismatch ◽  
Antiphase Domain ◽  
Multilayer Structures ◽  
Si Substrate ◽  
Mbe Growth ◽  
Etch Pit ◽  
Layer Structures ◽  
Domain Boundaries

ABSTRACTInvestigation has continued into the use of SixGe1−x multilayer structures (MLS) as a buffer layer between a Si substrate and a GaAs epitaxial layer in order to accommodate the 4.1% lattice mismatch. SixGe1−x 4-layer and 5-layer structures terminating in pure Ge have been grown using molecular beam epitaxy. Subsequent GaAs heteroepitaxy has allowed evaluation of these various GaAs/SixGe1−xMLS/Si (100) structures. Antiphase domain boundaries have been eliminated using vicinal Si (100) substrates tilted 6° off-axis toward [011], and the etch pit density in GaAs grown on a 5-layer SixGe1−x MLS on vicinal Si (lOO) was measured to be 106 cm−2.

scholarly journals Mechanical response of all-MoS2 single-layer heterostructures: a ReaxFF investigation

2016 ◽  
Vol 18 (34) ◽  
pp. 23695-23701 ◽  
Author(s):  
Bohayra Mortazavi ◽  
Alireza Ostadhossein ◽  
Timon Rabczuk ◽  
Adri C. T. van Duin
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Mechanical Response ◽  
Single Layer ◽  
Layer Structures

Mechanical properties of all-MoS2 single-layer structures at room temperature are explored using ReaxFF simulations.

Compact, flexible and highly selective wideband complementary FSS with high angular stability

2021 ◽  
pp. 1-17
Author(s):  
Srimita Coomar ◽  
Santanu Mondal ◽  
Rajarshi Sanyal
Keyword(s):  
Dielectric Material ◽  
Incident Angle ◽  
Single Layer ◽  
Angular Stability ◽  
Band Edge ◽  
Transmission Line Model ◽  
Layer Structures ◽  
Sharp Band ◽  
Lc Circuit ◽  
Very High

Abstract This article presents a novel miniaturized (0.105λ0 × 0.105λ0) flexible complementary frequency selective surfaces (CFSS) structure with sharp band edge selectivity and very high angular stability. To explore two diverse applications as a passband and stopband filter, a novel complementary convoluted square loop (CCSL) type structure has been designed and investigated on ultrathin dielectric material of thickness 0.0023λ0. The second-order wide controllable passband with fractional bandwidth of 19.23% (−3 dB) and remarkably wide stopband of 64.7% (−10 dB) and 54.8% (−20 dB) respectively have been achieved by using a cascaded resonating structure which is composed of asymmetrical meandered CCSL array, arranged on two ultrathin dielectric layers with air foam separation. This particular format would lead to sharp band edge selectivity with steep roll-off (72.43 dB/GHz) and an excellent passband selectivity factor (0.731). An equivalent lumped LC circuit in conjunction with the transmission line model has also been adopted to comprehend the physical mechanism of the proposed single layer and double layer structures. Further, better passband and stopband angular stability at an oblique incident angle of 45° and the bending characteristics have also been investigated thoroughly for the proposed flexible CFSS to check their employability in different conformal structures with WiMAX passband and WLAN stopband application.

Interfacial Sliding in Back-End Interconnect Structures in Microelectronic Devices

2002 ◽  
Vol 716 ◽  
Author(s):  
K.A. Peterson ◽  
C. Park ◽  
I. Dutta
Keyword(s):  
Dielectric Material ◽  
Single Layer ◽  
Component Reliability ◽  
Force Microscopy ◽  
Interfacial Sliding ◽  
Microelectronic Devices ◽  
Atomic Force ◽  
Layer Structures ◽  
Out Of Plane ◽  
Plane Step

AbstractDeformation of interconnect structures at the back-end of microelectronic devices during processing or service can have a pronounced effect on component reliability. Here, we use atomic force microscopy (AFM) to study plastic deformation and interfacial sliding of Cu interconnects lines on Si. The behavior of both stand-alone Cu lines and lines embedded in a low K dielectric was studied. Following thermal cycling, changes were observed in the in-plane Cu line dimensions, as well as the out-of plane step height between Cu and dielectric in single layer structures. These were attributed to differential deformation of the Cu/Si and Cu/dielectric material pairs due to thermal expansion mismatch, accommodated by interfacial creep. These results are discussed in light of previous work on the mechanism of interfacial creep. Some preliminary results on the distortion of Cu lines due to package-level stresses are also presented.

Guided Waves as an Online Monitoring Technology for Long-Term Operation in Nuclear Power Plants: Experimental Results on a Steam Discharge Pipe

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Francesco Bertoncini ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Complex Structure ◽  
Theoretical Background ◽  
Guided Wave ◽  
Experimental Results ◽  
Term Operation

Guided wave (GW) testing is regularly used for finding defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). By using magnetostrictive sensors, some issues, which usually limit the application to nuclear power plants (NPPs), can be fixed. The authors have already shown the basic theoretical background and simulation results concerning a real steel pipe, used for steam discharge, with a complex structure. On the basis of such theoretical framework, a new campaign has been designed and developed on the same pipe, and the obtained experimental results are now here presented as a useful benchmark for the application of GWs as nondestructive techniques. Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPPs components.

Numerical and Experimental Study on Soot Accumulation on the Wall of Falling Fuel Film Micro-Combustor

2010 ◽  
Author(s):  
Ning Mei ◽  
Xiaoyan Wang ◽  
Hongming Zhao ◽  
Yan Li ◽  
Hongyu Si
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Turbulence Model ◽  
Complex Structure ◽  
Flow Distribution ◽  
Experimental Results ◽  
Fuel Film ◽  
Numerical Result ◽  
Different Diameters ◽  
Micro Combustor

Fluid flow contributes much to fuel-air mixture formation in a micro-combustor, the RNG k-ε turbulence model was used to simulate the cold flow field of a falling fuel film microcombustor, and comparison was made between numerical result and experimental results. It is shown that the RNG k-ε turbulence model translated the flow field of a complex structure micro-combustor and the soot accumulation on the wall of combustion chamber. The experimental results showed that soot accumulation occurs in vortex backflow area near the wall of combustion chamber and the numerical methods is helpful for understanding the way of soot accumulation in the wall of combustion chamber. Therefore, modifications on the flow field with different diameters and entrance direction of the air flow into the primary combustion chamber were made. The numerical simulation of flow distribution showed that the flow field of micro-combustor could be ideal for eliminated soot accumulation.

scholarly journals An Improved Ball Pivot Algorithm-Based Ground Filtering Mechanism for LiDAR Data

2019 ◽  
Vol 11 (10) ◽  
pp. 1179 ◽  
Author(s):  
Wei Ma ◽  
Qingquan Li
Keyword(s):  
Spatial Relationship ◽  
Single Layer ◽  
Experimental Results ◽  
Lidar Data ◽  
Initial Surface ◽  
Seed Point ◽  
Pivot Algorithm ◽  
Group Iii ◽  
Digital Elevation ◽  
Elevation Model

Automatic ground filtering is an essential step for Digital Elevation Model (DEM) generation, which has significant application value. However, extraction and classification of ground points from the Light Detection and Ranging (LiDAR) data, especially in multitudinous terrain situations, is a challenging task because it is difficult to determine the set of optimal parameters for removing various non-ground features. In this paper, a new ground filtering technique based on an improved Ball Pivot Algorithm (BPA) is proposed. At the beginning, the LiDAR point cloud dataset was divided into different subsets based on the 2D regular grid. The lowest point in each grid was selected as the seed point to build a single-layer surface. After that, the improved BPA was executed to remove points on the higher location. Then, the rest of the points were calculated and selected as a new seed point according to the spatial relationship with the initial surface. Finally, non-ground points were filtered by means of improved BPA traversing all the grids. Our experimental results on the Benchmark dataset provided by the International Society for Photogrammetry and Remote Sensing (ISPRS) Working Group III/3 showed high accuracy (with a mean kappa coefficient over 80%) in terms of completeness, correctness, and quality for DEM generation. The experimental results demonstrated the proposed method is robust to various terrain situations, as it is more effective and feasible for ground filtering.

scholarly journals Blowhole Detection Based on Bidirectional Enhancement and Omnidirectional Analysis for X-Ray Inspection of Castings

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xinyue Zhao ◽  
Jingjing Liang ◽  
Zaixing He ◽  
Shuyou Zhang
Keyword(s):  
3D Model ◽  
Detection Method ◽  
Complex Structure ◽  
Model Fitting ◽  
Extraction Process ◽  
Experimental Results ◽  
Defect Region ◽  
Defect Identification ◽  
X Ray ◽  
Identification Process

Small blurred blowholes are difficult to detect, especially those in castings having a complex structure. In this paper, we propose a blowhole detection method based on bidirectional enhancement and omnidirectional analysis for X-ray inspection of castings. After obtaining the X-ray images of a casting from the X-ray inspection equipment, there are two main processes to detect the blowholes. First, in the extraction process for the potential defect region, we propose a method based on bidirectional enhancement that highlights the blurred defects and models the nondefective structure. Second, in the precise defect identification process, we propose a method to distinguish real defects by 3D model fitting-based omnidirectional analysis. The experimental results indicate that the proposed method has a higher performance in blowhole detection than comparable methods.

Experimental and finite element study on the single-layer reticulated composite joints

2020 ◽  
Vol 23 (10) ◽  
pp. 2174-2187
Author(s):  
Liang Zheng ◽  
Cheng Qin ◽  
Hong Guo ◽  
Dapeng Zhang ◽  
Mingtan Zhou ◽  
...  
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Wall Thickness ◽  
Great Influence ◽  
Single Layer ◽  
Experimental Results ◽  
Steel Pipe ◽  
Cover Plate ◽  
Element Analysis

In this article, a new type of reticulated joint, named the steel–concrete composite reticulated shell joint, is proposed. The proposed reticulated shell joint consists of an inner circular steel pipe, an outer circular steel pipe, a steel cover plate, and internal concrete. Five test specimens were tested under axial compression. The variable study included the wall thickness of the inner and outer circular steel pipes and the radius of the inner circular steel pipe. The test specimens exhibited a high bearing capacity and good plastic deformation ability under axial compression. The test results show that the wall thickness of the outer circular steel pipe and the radius of the inner circular steel pipe have a great influence on the bearing capacity of the steel–concrete composite reticulated shell joint, while the wall thickness of the inner circular steel pipe has little influence on the bearing capacity of the steel–concrete composite reticulated shell joint. Based on the test of the steel–concrete composite reticulated shell joints under axial load, the three-dimensional nonlinear finite element model was used to analyze the mechanical properties of the steel–concrete composite reticulated shell joints under axial compression. The results of the finite element analysis showed good agreement with the experimental results. The formula for calculating the bearing capacity of the joint is derived. By comparing with the experimental results, the calculated results are basically consistent with the experimental results.

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