Screw dislocation in a two‐phase isotropic thin film

1982 ◽  
Vol 53 (4) ◽  
pp. 3019-3023 ◽  
Author(s):  
S. N. G. Chu
Keyword(s):  
Thin Film ◽  
Screw Dislocation ◽  
Two Phase

scholarly journals Versatility of Nanocrystalline Silicon Films: from Thin-Film to Perovskite/c-Si Tandem Solar Cell Applications

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 759
Author(s):  
Luana Mazzarella ◽  
Anna Morales-Vilches ◽  
Lars Korte ◽  
Rutger Schlatmann ◽  
Bernd Stannowski
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Carrier Transport ◽  
Silicon Oxide ◽  
Short Circuit ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Silicon Films ◽  
Two Phase ◽  
Nanocrystalline Silicon Films

Doped hydrogenated nanocrystalline (nc-Si:H) and silicon oxide (nc-SiOx:H) materials grown by plasma-enhanced chemical vapor deposition have favourable optoelectronic properties originated from their two-phase structure. This unique combination of qualities, initially, led to the development of thin-film Si solar cells allowing the fabrication of multijunction devices by tailoring the material bandgap. Furthermore, nanocrystalline silicon films can offer a better carrier transport and field-effect passivation than amorphous Si layers could do, and this can improve the carrier selectivity in silicon heterojunction (SHJ) solar cells. The reduced parasitic absorption, due to the lower absorption coefficient of nc-SiOx:H films in the relevant spectral range, leads to potential gain in short circuit current. In this work, we report on development and applications of hydrogenated nanocrystalline silicon oxide (nc-SiOx:H) from material to device level. We address the potential benefits and the challenges for a successful integration in SHJ solar cells. Finally, we prove that nc-SiOx:H demonstrated clear advantages for maximizing the infrared response of c-Si bottom cells in combination with perovskite top cells.

A Two-Phase, Transient Model for the Cathode of a PEMFC Using Thin Film-Agglomerate Approach

2006 ◽  
Author(s):  
Hsin-Sen Chu ◽  
Shih-Ming Chang
Keyword(s):  
Thin Film ◽  
Steady State ◽  
Layer Thickness ◽  
Catalyst Layer ◽  
Critical Value ◽  
Gas Diffusion ◽  
Water Proton ◽  
Gaseous Species ◽  
Two Phase ◽  
Effect Of Water

This study presents a transient, one-dimensional, and two phase model of the proton exchange membrane fuel cell cathode. A thin film-agglomerate approach is applied to the catalyst layer. The model includes the transport of gaseous species, liquid water, proton, and electrochemical kinetics. The effect of water flooding both in the gas diffusion layer and catalyst layer in the cathode are investigated. The effects of agglomerate radius and the catalyst layer thickness on the overall cell performance are also investigated. The results show that the time for fuel cells to reach the steady state is in the order of 10 sec due to the effect of water accumulated both in the porous layer and the membrane. However the time for proton transport is in the order of 0.1 sec. In addition, before the ionic potential reaches the steady state, it would get a critical value. The critical value would depend on the operating cell voltage. There seems to be an optimum in the catalyst layer thickness and agglomerate radius.

Threading Screw Dislocations in a Two-Phase Plate and a Two-Phase Sphere

2018 ◽  
Vol 55 (1) ◽  
pp. 102-116 ◽  
Author(s):  
A.L. Kolesnikova ◽  
M.Yu. Gutkin ◽  
A.E. Romanov
Keyword(s):  
Screw Dislocation ◽  
Hollow Sphere ◽  
Phase Plate ◽  
Stress Distributions ◽  
Two Phase ◽  
Parallel Edge ◽  
Free Surfaces ◽  
Shear Moduli ◽  
Elastic Fields ◽  
First Time

Abstract A screw dislocation perpendicular to free surfaces and an interface in a two-phase plate, and a screw dislocation piercing a two-phase hollow sphere are considered. The analytical solutions of the boundary-value problems have been found for the first time with the help of the virtual defects technique. Elastic fields of the screw dislocation in the plate are presented in the form of integrals with Bessel functions. Elastic fields of the screw dislocation in the hollow sphere have the form of series with Legendre polynomials. Stress distributions in both of the considered geometries are plotted. The influence of the geometric parameters of the considered solids and the ratio of the shear moduli on the stresses is analyzed. The interaction of a screw dislocation with a parallel edge dislocation is discussed.

Numerical and Experimental Investigation of Bubble Dynamics via Electrowetting-on-Dielectric (EWOD)

2016 ◽  
Author(s):  
Sheng Wang ◽  
Junxiang Shi ◽  
Hsiu-Hung Chen ◽  
Tiancheng Xu ◽  
Chung-Lung (C. L.) Chen
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Bubble Dynamics ◽  
Bubble Diameter ◽  
Experimental System ◽  
Hydrophobic Surface ◽  
Numerical Results ◽  
The Body ◽  
Two Phase ◽  
Electrowetting On Dielectric

With the inspiration from electrowetting-controlled droplets, the potential advantages of electrowetting for bubble dynamics are investigated experimentally and numerically. In our experimental system, a 100 nanometer thin film gold metal was used as an electrode, and a 6.5 micrometer polydimethylsiloxane (PDMS) was spin-coated on the electrode acting both as an dielectric layer and hydrophobic surface. A two-phase model coupled with a electrostatics was used in our simulation work, where the body force due to the electric field acts as an external force. Our numerical results demonstrated that electrowetting can help the detachment of a small bubble by changing the apparent contact angle. Similar results were observed in our experiments that with electrowetting on dielectric, the contact angle of bubble on a hydrophobic surface will obviously decrease when a certain electrical field is applied either with a small size bubble (diameter around 1mm) or a relatively larger size bubble (diameter around 3 mm). When the applied voltage becomes high enough, both the experimental and numerical results demonstrate the characteristics of bubble detachment within a thin film liquid layer.

Stacked screw dislocation arrays in an anisotropic two-phase medium

1973 ◽  
Vol 4 (4) ◽  
pp. 1171-1172 ◽  
Author(s):  
K. Jagannadham ◽  
K. S. Raghavan
Keyword(s):  
Screw Dislocation ◽  
Two Phase ◽  
Dislocation Arrays ◽  
Phase Medium

scholarly journals Wicking and Thermal Characteristics of Micropillared Structures for Use in Passive Heat Spreaders

2011 ◽  
Author(s):  
Ram Ranjan ◽  
Abhijeet Patel ◽  
Suresh V. Garimella ◽  
Jayathi Y. Murthy
Keyword(s):  
Thin Film ◽  
Thermal Contact ◽  
Thermal Characteristics ◽  
Hydrodynamic Performance ◽  
Superior Performance ◽  
High Permeability ◽  
Two Phase ◽  
Thin Film Evaporation ◽  
Film Evaporation ◽  
Cooling Devices

The thermal and hydrodynamic performance of passive two-phase cooling devices such as heat pipes and vapor chambers is limited by the capabilities of the capillary wick structures employed. The desired characteristics of wick microstructures are high permeability, high wicking capability and large extended meniscus area that sustains thin-film evaporation. Choices of scale and porosity of wick structures lead to tradeoffs between the desired characteristics. In the present work, models are developed to predict the capillary pressure, permeability and thin-film evaporation rates of various micropillared geometries. Novel wicking geometries such as conical and pyramidal pillars on a surface are proposed which provide high permeability, good thermal contact with the substrate and large thin-film evaporation rates. A comparison between three different micropillared geometries — cylindrical, conical and pyramidal — is presented and compared to the performance of conventional sintered particle wicks. The present work demonstrates a basis for reverse-engineering wick microstructures that can provide superior performance in phase-change cooling devices.

scholarly journals Screw dislocation in a thin film with surface effects

2017 ◽  
Vol 110-111 ◽  
pp. 89-93 ◽  
Author(s):  
Ming Dai ◽  
Peter Schiavone ◽  
Cun-Fa Gao
Keyword(s):  
Thin Film ◽  
Screw Dislocation ◽  
Surface Effects
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