Recent developments in III–V semiconducting nanowires for high-performance photodetectors

2017 ◽  
Vol 1 (4) ◽  
pp. 630-645 ◽  
Author(s):  
Lifan Shen ◽  
Edwin Y. B. Pun ◽  
Johnny C. Ho

We present a comprehensive overview of the recent advances in III–V NW-based photodetectors operating in the UV, visible and infrared spectra range.

Author(s):  
Paul С. Uzoma ◽  
Huan Hu ◽  
Mahdi Khadem ◽  
Oleksiy V. Penkov

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN, and Black Phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear, and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 897
Author(s):  
Paul C. Uzoma ◽  
Huan Hu ◽  
Mahdi Khadem ◽  
Oleksiy V. Penkov

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN and black phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.


Synthesis ◽  
2021 ◽  
Author(s):  
Qing-Zhu Li ◽  
Wen-Lin Zou ◽  
Zhi-Qiang Jia ◽  
Jun-Long Li

Allyl and propargyl sulfonium salts are readily available reagents and have recently emerged as versatile building blocks in the assembly of cyclic skeletons. As an alternative to the classical sulfonium salts, allyl and propargyl sulfonium salts can convert to the corresponding vinyl sulfur ylide or allenic sulfonium salt intermediates that contain diverse nucleophilic or electrophilic reactive positions, thereby enabling a great variety of annulation reactions. In this review, we provide a comprehensive overview of the recent developments on this growing field by summarizing the annulation reactions involving allyl and propargyl sulfonium salts.


Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 265
Author(s):  
Amalia Miliou

In-fiber interferometric-based sensors are a rapidly growing field, as these sensors exhibit many desirable characteristics compared to their regular fiber-optic counterparts and are being implemented in many promising devices. These sensors have the capability to make extremely accurate measurements on a variety of physical or chemical quantities such as refractive index, temperature, pressure, curvature, concentration, etc. This article is a comprehensive overview of the different types of in-fiber interferometric sensors that presents and discusses recent developments in the field. Basic configurations, a brief approach of the operating principle and recent applications are introduced for each interferometric architecture, making it easy to compare them and select the most appropriate one for the application at hand.


Textiles ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 433-465
Author(s):  
Philip R. Barnett ◽  
Hicham K. Ghossein

Carbon fiber recycling has garnered significant attention in recent years due to the large volume of manufacturing waste and upcoming end-of-life products that will enter the waste stream as the current generation of aircraft is retired from service. Recycled carbon fibers have been shown to retain most of their virgin mechanical properties, but their length is generally reduced such that continuous fiber laminates cannot be remade. As such, these fibers are typically used in low-performance applications including injection molding, extrusion/compression molding, and 3D printing that further degrade the fiber length and resulting composite properties. However, recent advances in the processing of long discontinuous fiber textiles have led to medium- to high-performance composites using recycled carbon fibers. This review paper describes the recent advances in recycled carbon fiber textile processing that have made these improvements possible. The techniques used to manufacture high-value polymer composites reinforced with discontinuous recycled carbon fiber are described. The resulting mechanical and multifunctional properties are also discussed to illustrate the advantages of these new textile-based recycled fiber composites over the prior art.


Author(s):  
S. Yegnasubramanian ◽  
V.C. Kannan ◽  
R. Dutto ◽  
P.J. Sakach

Recent developments in the fabrication of high performance GaAs devices impose crucial requirements of low resistance ohmic contacts with excellent contact properties such as, thermal stability, contact resistivity, contact depth, Schottky barrier height etc. The nature of the interface plays an important role in the stability of the contacts due to problems associated with interdiffusion and compound formation at the interface during device fabrication. Contacts of pure metal thin films on GaAs are not desirable due to the presence of the native oxide and surface defects at the interface. Nickel has been used as a contact metal on GaAs and has been found to be reactive at low temperatures. Formation Of Ni2 GaAs at 200 - 350C is reported and is found to grow epitaxially on (001) and on (111) GaAs, but is shown to be unstable at 450C. This paper reports the investigations carried out to understand the microstructure, nature of the interface and composition of sputter deposited and annealed (at different temperatures) Ni-Sb ohmic contacts on GaAs by TEM. Attempts were made to correlate the electrical properties of the films such as the sheet resistance and contact resistance, with the microstructure. The observations are corroborated by Scanning Auger Microprobe (SAM) investigations.


2020 ◽  
Author(s):  
James McDonagh ◽  
William Swope ◽  
Richard L. Anderson ◽  
Michael Johnston ◽  
David J. Bray

Digitization offers significant opportunities for the formulated product industry to transform the way it works and develop new methods of business. R&D is one area of operation that is challenging to take advantage of these technologies due to its high level of domain specialisation and creativity but the benefits could be significant. Recent developments of base level technologies such as artificial intelligence (AI)/machine learning (ML), robotics and high performance computing (HPC), to name a few, present disruptive and transformative technologies which could offer new insights, discovery methods and enhanced chemical control when combined in a digital ecosystem of connectivity, distributive services and decentralisation. At the fundamental level, research in these technologies has shown that new physical and chemical insights can be gained, which in turn can augment experimental R&D approaches through physics-based chemical simulation, data driven models and hybrid approaches. In all of these cases, high quality data is required to build and validate models in addition to the skills and expertise to exploit such methods. In this article we give an overview of some of the digital technology demonstrators we have developed for formulated product R&D. We discuss the challenges in building and deploying these demonstrators.<br>


The essays collected in this book represent recent advances in our understanding of speech acts-actions like asserting, asking, and commanding that speakers perform when producing an utterance. The study of speech acts spans disciplines, and embraces both the theoretical and scientific concerns proper to linguistics and philosophy as well as the normative questions that speech acts raise for our politics, our societies, and our ethical lives generally. It is the goal of this book to reflect the diversity of current thinking on speech acts as well as to bring these conversations together, so that they may better inform one another. Topics explored in this book include the relationship between sentence grammar and speech act potential; the fate of traditional frameworks in speech act theory, such as the content-force distinction and the taxonomy of speech acts; and the ways in which speech act theory can illuminate the dynamics of hostile and harmful speech. The book takes stock of well over a half century of thinking about speech acts, bringing this classicwork in linewith recent developments in semantics and pragmatics, and pointing the way forward to further debate and research.


2021 ◽  
Vol 44 (3) ◽  
Author(s):  
Yi Tian ◽  
Naisen Yu ◽  
Shiyu Du ◽  
Dedi Liu ◽  
Yunfeng Wu
Keyword(s):  

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