Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Analysis of Heat Conduction in Silicon Using Molecular Dynamics Simulations

2006 ◽  
Author(s):  
Asegun S. Henry ◽  
Gang Chen
Keyword(s):  
Molecular Dynamics ◽  
Lattice Dynamics ◽  
Crystalline Silicon ◽  
Relaxation Times ◽  
Normal Modes ◽  
Md Simulations ◽  
Dynamics Simulations ◽  
Technological Significance ◽  
Fitting Parameters ◽  
Phonon Properties

Silicon's material properties, have been studied extensively because of its technological significance in a variety of industries, including microelectronics. Yet, questions surrounding the phonon relaxation times in silicon continue to linger.1,2 Previous theoretical works3-5 have generated qualitative expressions for phonon relaxation times, however these approaches require fitting parameters that cannot be determined reliably. This paper first discusses implementation issues associated with using the Green-Kubo method in molecular dynamics (MD) simulations. We compare various techniques used in similar works and discusses several implementation issues that have arisen in the literature. We then describe an alternative procedure for analyzing the normal modes of a crystal to extract phonon relaxation times. As an example material we study bulk crystalline silicon using equilibrium MD simulations and lattice dynamics. The environment dependent interatomic potential6 is used to model the interactions and frequency dependent phonon properties are extracted from the MD simulations.

Mechanism and Model of Bond Formation in Ultrasonic Wire Bonding

2015 ◽  
Author(s):  
T. Calvin Tszeng
Keyword(s):  
Flip Chip ◽  
Critical Phenomenon ◽  
Bond Formation ◽  
Interfacial Shear Stress ◽  
Wire Bonding ◽  
Micromechanics Model ◽  
Ultrasonic Bonding ◽  
Microelectronic Devices ◽  
Ultrasonic Wire Bonding ◽  
Technological Significance

Despite being a critical phenomenon of tremendous technological significance in ultrasonic flip-chip and wire bonding processes of today’s microelectronic devices, interfacial bond formation still calls for better understanding at a fundamental level. The goal of the research is to improve these processes through better understanding and modeling of bond formation. This paper presents a micromechanics model that addresses increasing contact area during ultrasonic cyclic loading cycle. The micromechanics model provides interfacial shear stress as boundary condition to FEM simulations of ultrasonic bonding processes. Comparison between preliminary results and experimental data is conducted.

Hertz and the Technological Significance of Electromagnetic Waves

Isis ◽  
1965 ◽  
Vol 56 (3) ◽  
pp. 342-345 ◽  
Author(s):  
Charles Süsskind
Keyword(s):  
Electromagnetic Waves ◽  
Technological Significance

scholarly journals Programmable photoresponsive materials based on a single molecule via distinct topochemical reactions

2021 ◽  
Author(s):  
Xiao Wei ◽  
Bao Li ◽  
Zhiqiang Yang ◽  
RongLin Zhong ◽  
Yufei Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Single Molecule ◽  
Topochemical Reactions ◽  
Technological Significance

Engineering the preorganization of photoactive units remains a big challenge in solid-state photochemistry research. It is of not only theoretical importance in construction of topochemical reactions but also technological significance...

The Performance of Standard Setting Organizations

2011 ◽  
pp. 95-108
Author(s):  
Marc Rysman ◽  
Tim Simcoe
Keyword(s):  
Standard Setting ◽  
Marginal Impact ◽  
Setting Process ◽  
Technological Significance

This article uses citations to patents disclosed in the standard setting process to measure the technological significance of voluntary standard setting organizations (SSOs). We find that SSO patents are outliers in several dimensions and importantly, are cited far more frequently than a set of control patents. More surprisingly, we find that SSO patents receive citations for a much longer period of time. Furthermore, we find a significant correlation between citation and the disclosure of a patent to an SSO, which may imply a marginal impact of disclosure. These results provide the first empirical look at patents disclosed to SSO’s, and show that these organizations both select important technologies and play a role in establishing their significance.

Development of Gold Electrodes for Microbial Fuel Cells

2016 ◽  
Vol 19 (1) ◽  
pp. 037-042 ◽  
Author(s):  
L. Verea ◽  
M. Jaramillo-Torres ◽  
M. P. Mejia-Lopez ◽  
J. Campos ◽  
P. J. Sebastian
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cell ◽  
Microbial Fuel Cells ◽  
Large Scale ◽  
Simple Technique ◽  
Reduction Reaction ◽  
Thin Layers ◽  
Different Temperatures ◽  
Electrode Fabrication ◽  
Technological Significance

The microbial fuel cell (MFC) has been an important subject of study in the last decades because of its technological significance that one can produce hydrogen or electricity by wastewater treatment (bio-remediation). One of the main issues for the application of these devices on large scale is the processes and materials for the electrode fabrication. The cathode for MFC requires a catalyst to perform the reduction reaction and this work presents a simple technique to obtain thin layers of gold (TLG) supported on glass. This technique was employed to obtain TLG with different thicknesses from 848 nm to the thinnest of 137 nm. Since the gold of the TLGs presented adherence issues, a successful thermal treatment with different temperatures from 150-300 ºC was developed to avoid the gold detachment. The TLGs were tested as cathodes in a MFC and a maximum Voc of 431 mV and an Isc of 10 × 10−2 mA were obtained. The process to obtain TLGs presented here has probed to be a good option for this application since the thickness obtained and the accessible material (glass) employed as support offers a solution to the costs and the scaling issues.

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