Tungsten Crucible Made Sapphire Wafers - Fingerprint Identification

In 2013 Apple Computer Inc. introduced Iphone5S. The eye-catching not only in its colors but the innovative fingerprint identification also impresses many people. With the popularity of mobile phone fingerprint identification, now many smart phones all you can think of have fingerprint identification. Fingerprint identification technology has not only become the standard configuration of smart phones, but more to help people protect the phone and personal privacy.
 
Cover material of fingerprint identification sensor are: ceramics, sapphire and resins. As we knew sapphire has lots of good property which can widely used in mobile phones fingerprinting identification technology and the main advantages are as follows:
1. The phone reads the fingerprint data required to have a very fast speed of sensors. Sapphire wafer has high dielectric constant and good thermal conductivity which can rapid response fingerprint data.
2. Phone fingerprint identification system is very sensitive, if the recognition area is scratched, it will cause recognition failure. It requires fingerprint identification plate with high strength, wear resistance and other properties. The hardness of sapphire wafer is 9H (Mohs hardness) and has good scratch resistance, to better protect the identification system.
3. The fingerprint area in front cover produced by sapphire wafer is kind of mirror which is similar with phone cover glass, making the phone more harmonious overall appearance.
 
Having high purity, high density, crack-free, precise size, smooth inner and outer walls of the tungsten crucibles for sapphire crystal growth and performance has played an important role. 
Tungsten Crucible Made Sapphire Wafers

Ammonium Metatungstate(AMT) Industry China Market Research Report 2016

Ammonium Metatungstate(AMT)Ammonium Metatungstate(AMT)

The China Ammonium Metatungstate(AMT) Industry 2016 Market Research Report is a professional and in-depth study on the current state of the Ammonium Metatungstate(AMT) industry.

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Russia Plans to Carry Out a Test for Destroying Asteroid by Nuclear Bomb

nuclear bomb destroyed asteroidnuclear bomb destroyed asteroid

Recently, according to foreign media reports, Russia wants to carry out a nuclear bomb upgrade plan, namely that to emission the nuclear bomb outside of the atmosphere through the intercontinental ballistic missile, in order to destroy asteroids, which would pose a threat to earth. 

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King of New Materials - Graphene Will Subvert the Future Battlefield, China to Build a Pilot Industry

Britain has developed a new technology on rapidly mass production; and Chinese experts successfully developed industrial prospect broad Graphene super battery. The Ministry of industry, national development and Reform Commission and the Ministry of science issued Number Opinions on Accelerating Graphene Industry Innovation and Development. Graphene not only has a broad application prospects in the future, but also will bring disruptive change in the future battlefield.

Graphene carbon structure model

Some scholars said: "nineteenth Century is Iron Age, twentieth Century is Silicon Age, and Twenty-one century is Carbon Age." And Graphene is a representative material of carbon Age. Graphene is stripped out from graphite material, composed of carbon atoms of only one atomic layer, a two-dimensional carbon films with hexagonal honeycomb lattice (benzene). Graphene is a hard material with magic properties of high transmittance, low energy loss. Although graphene has not yet been put into mass production stage, but its excellent performance makes people be full of expectations on the application of future battlefield.
In addition, Graphene is almost zero penetration for gas, liquid and so on. That means coating the ship with Graphene equals to wear a suit of armor "invulnerability". These amazing features also allow Graphene becoming recognized as the king of new materials in just a few decades.

According to opinions, in the future, Graphene will have broad applications on aerospace, weapons and equipment, major infrastructure, and new energy, new energy automotive, energy saving and environmental protection, electronic information and other fields.

 

The United States Worrying China to Sell Semiconductor Equipment at Cabbage Price and Rejected China Takeover of Philps

On February 5,New York Times publishedAmerican worrying about Chinese ambition in chip is daily increasing, the article said," China is investing heavily to build the domestic semiconductor industry, the upgrade its military forces and local technology industry's move caused by Washington's attention ". In late January 2016, the U.S. foreign investment committee rejected the Chinese investors take over PHILPS's lighting business at 2 billion 900 million, which is a concrete manifestation of the U.S. government concerns.

So, why the United States obstructed the acquisition? The United States government to stop is not the lighting business itself, but to prevent Chinese investors master the technology of the third generation semiconductor materials—GaN, through the acquisition of Philips’s lighting business. LED of GaN has the smaller appearance, higher power and luminosity than the traditional LED; more critical, the density power of GaN is 10 times of the existing GaAs, which can not only widely be used in communication base station, motor vehicles, electric vehicles, wind power and other civilian areas, but also used in the special fields of phased array radar, and make it became a hotspot and frontier of global semiconductor research.

The reason why U.S government stops Chinese investors’ acquisition of Philips’s lighting business is not just for the considering of technology in military applications and national security, but also for restrains the development of China's semiconductor industry, keep its advantage in technology technical.

In short, China support of the local development of the semiconductor industry in the from of semiconductor, IC design, manufacturing, packaging and testing, semiconductor manufacturing equipment, a full range of support, and strive to achieve a "winner" in the form of the whole industry chain. Once the semiconductor industry captured by China, and output the products at "cabbage price", it can weaken American global supremacy material basis on the one hand; on the other hand, it will make China completely get rid of controlled by others in the field of information technology and the harmful situation of information security, presumably this is what Americans really worries.

Tungsten Diselenide is Expected to as Thin Flexible Solar Cells

This thin layer is thin and light, about 95% of the light can pass through it, but one-tenth of the remaining 5% of the light will be absorbed by the material, and converted into electricity. Therefore, its internal efficiency is very high. If multiple thin layers have stacks, a large part of this incident light ray can be effectively utilized ── but sometimes this high transparency may have beneficial side effects.
 
A analyst said, tungsten diselenide applications and touted graphene are currently just the same concept, the future of the specific application is not clear yet, it’s hard to make investment decisions. Researchers of Shanghai research unit long-term study of flexible battery also said that the tungsten diselenide thin flexible solar cell applications are forward-looking research, further away from the application.
 
"We can imagine the solar cell layer stack on the glass curtain, may allow some light into the building, but also to bring power available," Mueller said.
 
Most standard solar cells are made of silicon produced, which is not only quite cumbersome and inflexible. The organic material can be used for optoelectronic applications, but the degree of degradation is quite fast. "2D structure of a single atomic layer has a big advantage is that its crystalline properties. The crystal structure adds to stability," Mueller explained.

tungsten diselenide

Tungsten Diselenide has been Developed as New Flexible Solar Cell Materials in Austria

Vienna University of Technology in Austria has been the first developed the diode made by tungsten diselenide (WSe2). According to the experiment, this material can be used for ultra-thin flexible solar cells. It was expected in the market that it will take the place of graphene to become the next new-material concept, scientific experts and related enterprises indicates that the application of prospective studies are currently unclear.
 
Graphene is considered as one of the most promising electronic material, but it’s not suitable for build solar cells, which is why the Vienna University of Technology research team began to look for other similar materials like graphene, they want to find the one material that can be arranged by ultra-thin layers and has better electronic properties. Therefore, the researchers found tungsten diselenide, and its main structure is that the upper and lower layer of selenium connected to an intermediate layer of tungsten atoms, as graphene can absorb light, about 95% of the light can pass through it, but one-tenth of the remaining 5% of the light will be absorbed by the material, and converted into electricity.

WSe2

Physical Properties of WTe2 under High Pressure and Strong Magnetic Field II

Stress can make lattice shrink, increase energy band overlap, destroy this balance between carriers, which may induce a new electronic phase transition. Based on this consideration, cooperation team at Nanjing University of Artificial Microstructure Collaborative Innovation Center under the framework of the research carried out quickly both experimental and theoretical high pressure.
 
It was found that: at a pressure of 2.7GPa, when the temperature dropped to 3.1K or less, along with the gradual disappearance of the giant magnetoresistance effect, there was a sharp decline of the resistance. With further increase of the pressure, the emergence of zero resistance appear gradually, indicating the resistance steep drop corresponds to a stress-induced superconducting transition. At about 17GPa, the superconducting transition temperature TC reaches the maximum of 7K, and the accompanying pressures continue to increase, TC gradually decreased, showing a phase diagrama of superconducting pressure as a "dome" type. The study of different external magnetic field at high pressure resistance and magnetic susceptibility has been the further evidence of the existence of superconductivity. On the other hand, Theoretical calculations of high-pressure related show that TC beginning to increase with increasing pressure is the results of increasing density of states near the Fermi surface, and decreases of TC under higher pressure is attributed to the lattice structure instability.

Physical Properties of WTe2 under High Pressure and Strong Magnetic Field I

Recently, Chinese Academy of Sciences Hefei Physical Institute of Solid State Physics, and the collaborative research team of Nanjing University and a strong magnetic field center, made new progress on the study of the WTe2 material physical properties under high pressure high magnetic field extreme conditions. The team used high-pressure diamond anvil cell technology, by studying the electrical transport and magnetic susceptibility, for the first time that observed the superconductivity of high-pressure-induced and magnetic resistance calculated by the theory of evolution and the superconductivity with pressure has been systematically studied, related to the results of "superconductivity and evolution of the electronic structure of the type" and titled by "tungsten telluride pressure-driven", published in "Nature - communication" on July 23, the solid researcher YangZhaorong and professor at Nanjing University Song Fengqi, Wan Xiangang are co-corresponding authors of this article.
 
High pressure is a clean, pure and powerful tool in researching new material properties, especially in the exploration of new superconducting materials. WTe2 is a kind of layered semi-metallic material, when the temperature is 0.53K, under strong magnetic field at 60T, the magnetoresistance can be up to 13,000,000%, and it still did not reach the saturation. This strange phenomenon has aroused wide attention of researchers at home and abroad. Recent theoretical studies suggest that it may be a kind of Weyl semi-metallic, magnetic resistance is considered to be related to the perfect match of the hole and electron carrier concentration of the Fermi surface nearby in the system, of which this perfect equilibrium is extremely sensitive for external perturbation, such as doping and stress.

WTe2

 

Study on Unique Electronic Valleys of Tungsten Disulfide

Monolayer films of tungsten disulfide, just three atoms thick, have unique electronic valleys which can be manipulated with laser light. This finding, by MIT physics graduate student Edbert Jarvis Sie, Associate Professor Nuh Gedik, and colleagues, was significant enough to warrant placement on the cover of Nature Materials earlier this year.
 
The cover illustrates a tornado-like whorl of light, lifting an electronic band in the material to a higher energy state, which widens the band gap in the material. This widening is known as the optical Stark effect. The researchers, under senior author Nuh Gedik, the Lawrence C. (1944) and Sarah W. Biedenharn Career Development Associate Professor of Physics at MIT, found that applying circularly polarized laser light lifted the energy in one valley while leaving the energy in the other valley unaffected. "There are two valleys. If we switch the laser polarization, the effect switches to the other valley," Sie says. Gedik spoke about his group's research on topological insulators at the Materials Day Symposium, on Oct. 14, in Kresge Auditorium.
 
"In materials, electrons travelling in different directions experience different scattering potential with the atoms. This establishes an energy landscape as a function of electron's momentum, which can form a local minimum that we call a valley," Sie explains. "The phenomenon of the valleys only occurs in these extremely thin, monolayer forms of the tungsten sulfur compound, not in its bulk form. These valleys normally have the same energy. But as we apply this circularly polarized light, we can lift the energy of one valley relative to the other."

WTe2

 

 

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