轻点灬大ji巴太粗太长了h-轻点灬大ji巴太粗太长了啊h-轻点灬大ji巴太粗太长了爽文-轻点灬大ji巴太大太深了-japan高清视频乱xxxxx-jiuma和我啪啪

新聞動態
NEWS
Location:Chinese Academy of Sciences > NEWS  > News in field Graphene

Press release Ultralow-power operation of future nanoelectronic chips is enabled by Mexican hat in bilayer graphene

Come: Chinese Academy of Sciences    Date: 2016-05-30 16:16:31


       Scientists have developed a new type of graphene-based transistor and using modelling they have demonstrated that it has ultralow power consumption compared with other similar transistor devices. The findings have been published in a paper in the journal Scientific Reports. The most important effect of reducing power consumption is that it enables the clock speed of processors to be increased. According to calculations, the increase could be as high as two orders of magnitude.
 
"The point is not so much about saving electricity - we have plenty of electrical energy. At a lower power, electronic components heat up less, and that means that they are able to operate at a higher clock speed - not one gigahertz, but ten for example, or even one hundred," says the corresponding author of the study, the head of MIPT‘s Laboratory of Optoelectronics and Two-Dimensional Materials, Dmitry Svintsov.
 
Building transistors that are capable of switching at low voltages (less than 0.5 volts) is one of the greatest challenges of modern electronics. Tunnel transistors are the most promising candidates to solve this problem. Unlike in conventional transistors, where electrons "jump" through the energy barrier, in tunnel transistors the electrons "filter" through the barrier due to the quantum tunneling effect. However, in most semiconductors the tunneling current is very small and this prevents transistors that are based on these materials from being used in real circuits.
 
The authors of the article, scientists from the Moscow Institute of Physics and Technology (MIPT), the Institute of Physics and Technology RAS, and Tohoku University (Japan), proposed a new design for a tunnel transistor based on bilayer graphene, and using modelling, they proved that this material is an ideal platform for low-voltage electronics.
 
Graphene, which was created by MIPT alumni Sir Andre Geim and Sir Konstantin Novoselov, is a sheet of carbon that is one atom thick. As it has only two dimensions, the properties of graphene, including its electronic properties, are radically different to three-dimensional carbon - graphite.
 
"Bilayer graphene is two sheets of graphene that are attached to one another with ordinary covalent bonds. It is as easy to make as monolayer graphene, but due to the unique structure of its electronic bands, it is a highly promising material for low-voltage tunneling switches," says Svintsov.
 
Bands of bilayer graphene, i.e. the allowed energy levels of an electron at a given value of momentum, are in the shape of a "Mexican hat" (compare this to the bands of most semiconductors which form a parabolic shape). It turns out that the density of electrons that can occupy spaces close to the edges of the "Mexican hat" tends to infinity - this is called a van Hove singularity. With the application of even a very small voltage to the gate of a transistor, a huge number of electrons at the edges of the "Mexican hat" begin to tunnel at the same time. This causes a sharp change in current from the application of a small voltage, and this low voltage is the reason for the record low power consumption.
 
In their paper, the researchers point out that until recently, van Hove singularity was barely noticeable in bilayer graphene - the edges of the "Mexican hat" were indistinct due to the low quality of the samples. Modern graphene samples on hexagonal boron nitride (hBN) substrates are of much better quality, and pronounced van Hove singularities have been experimentally confirmed in the samples using scanning probe microscopy and infrared absorption spectroscopy.
 
An important feature of the proposed transistor is the use of "electrical doping" (the field effect) to create a tunneling p-n junction. The complex process of chemical doping, which is required when building transistors on three-dimensional semiconductors, is not needed (and can even be damaging) for bilayer graphene. In electrical doping, additional electrons (or holes) occur in graphene due to the attraction towards closely positioned doping gates.
 
Under optimum conditions, a graphene transistor can change the current in a circuit ten thousand times with a gate voltage swing of only 150 millivolts.
 
"This means that the transistor requires less energy for switching, chips will require less energy, less heat will be generated, less powerful cooling systems will be needed, and clock speeds can be increased without the worry that the excess heat will destroy the chip," says Svintsov.

< Previous Nanographene toughens polymeric mater...Graphene doped with hydrogen reveals ... Next >

?
Tel:+86-28-85241016,+86-28-85236765    Fax:+86-28-85215069,+86-28-85223978    E-mail:carbon@cioc.ac.cn,times@cioc.ac.cn,nano@cioc.ac.cn
QQ:800069832    Technical Support ac57.com
Copyright © Chengdu Organic Chemicals Co. Ltd., Chinese Academy of Sciences 2003-2025. manage 蜀ICP備05020035號-3
主站蜘蛛池模板: 最新一本大道香蕉综合 | 日日狠狠久久8888av | 日韩免费视频一区 | 国产女女互摸互慰在线观看 | 日韩精品中文字幕一区二区三区 | 亚洲国产剧情在线 | 成人免费动作大片黄在线 | 国产香蕉精品视频在 | 久久加久久 | 一级国产精品一级国产精品片 | 国产丝袜视频 | 欧美日韩不卡视频一区二区三区 | 一级做a爱片性色毛片武则天五则 | 在线免费看a爱片 | 亚洲激情小视频 | 国产精品不卡在线观看 | 亚洲欧美强伦一区二区另类 | 久操短视频 | 国产成人手机在线 | 国产97视频在线 | 国产亚洲精品观看91在线 | 老司机精品久久最新免费 | 一级做a免费视频观看网站 一男一女下面一进一出性视频 | 免费成人在线网站 | 久久高清精品 | 欧美午夜视频一区二区三区 | 成人资源在线 | 欧美性高清另类videosex | 成人欧美精品一区二区不卡 | 亚洲日本va中文字幕在线不卡 | 成人在线观看播放 | 美日韩一区二区三区 | 日韩一区二区三区免费体验 | 久久狠色噜噜狠狠狠狠97 | 日本特交大片免费观看 | 亚洲成a人片在线观看导航 亚洲成a人片在线观看精品 | 国产成人拍精品视频网 | 午夜影院一区二区 | 国产1区在线观看 | 一个人看的www网站 一个人看的www在线 | 日本视频免费高清一本18 |