- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
The silicon transistors in your computer may be replaced in ten years by transistors based on carbon nanotubes. This is what scientists at the University of Gothenburg are hoping - they have developed a method to control the nanotubes during production.
By Krister Svahn
Silicon is subject to certain limitations, and industry is looking for a replacement. The electronics industry has net annual sales of over USD 200 billion, and this means that the development is being fuelled by powerful forces.
Scientist Johannes Svensson from the Department of Physics at the University of Gothenburg has investigated the manufacture and use of carbon nanotubes in his PhD thesis.
Faster and smaller
"I don't believe that it will be cheaper to build transistors from another material than silicon, but carbon nanotubes can be used to produce smaller and faster components. This will also result in computers that consume less energy" says Johannes Svensson.
The amazing development in computer power that has taken place after the invention of the integrated circuit in the 1950s has been made possible by the transistor, which is the most important component of all processors, becoming ever-faster.
Increase the speed
The most common semiconductor material in transistors is silicon, since it is cheap and easy to process. But silicon has its limitations. As the size of the transistors is reduced in order to increase their speed, problems arise that lead to, among other things, increased energy consumption and large variation in the transistor properties.
By exchanging the silicon in the channel for a carbon nanotube, the transistors can be made both smaller and faster than today's transistors. A carbon nanotube is a molecule in form of a hollow cylinder with a diameter of around a nanometer (roughly 1/50,000 of the width of a human hair) which consists of pure carbon. Some carbon nanotubes are semiconducting, and this means that they can be used in transistors, although there are several problems that must be solved before they can be connected together to form large circuits.
"Carbon nanotubes grow randomly and it is not possible to control either their position or direction. Therefore I have applied an electrical field to guide the tubes as they grow," says Johannes Svensson.
Built his own
One of the effects of the electric field is that most of the carbon nanotubes lie in the same direction.
"In order to show that it is possible to build electronic components that contain only carbon nanotubes, I have built a transistor which not only has a carbon nanotube as its channel, but also another nanotube which is used as the electrode that controls the current."
Another problem that must be solved when integrating nanotubes into larger circuits is the difficulty of manufacturing good metal contacts for the tubes. Johannes' research has shown that the properties of the contacts depend on the diameter of the nanotubes. Choosing the correct diameter will allow good contacts with a low resistance to be achieved.
The thesis Carbon Nanotube Transistors: Nanotube Growth, Contact Properties and Novel Devices was successfully defended at a disputation held on 7 May 2010.
Link to the thesis hdl.handle.net/2077/21859
For more information, please click here
Department of Physics
University of Gothenburg
Mobile: +46 768 539891
Tel: +46 31 772 3435
+46 31 786 49 12
Copyright © University of GothenburgIf you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
|Related News Press|
News and information
Deep Space Industries and SFL selected to provide satellites for HawkEye 360ís Pathfinder mission: The privately-funded space-based global wireless signal monitoring system will be developed by Deep Space Industries and UTIAS Space Flight Laboratory May 26th, 2016
Revealing the nature of magnetic interactions in manganese oxide: New technique for probing local magnetic interactions confirms 'superexchange' model that explains how the material gets its long-range magnetic order May 25th, 2016
Graphene: Progress, not quantum leaps May 23rd, 2016
Albertan Science Lab Opens in India May 7th, 2016
Gigantic ultrafast spin currents: Scientists from TU Wien (Vienna) are proposing a new method for creating extremely strong spin currents. They are essential for spintronics, a technology that could replace today's electronics May 25th, 2016
Dartmouth team creates new method to control quantum systems May 24th, 2016
Attosecond physics: A switch for light-wave electronics May 24th, 2016
Programmable materials find strength in molecular repetition May 23rd, 2016
Researchers demonstrate size quantization of Dirac fermions in graphene: Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices May 20th, 2016
New type of graphene-based transistor will increase the clock speed of processors: Scientists have developed a new type of graphene-based transistor and using modeling they have demonstrated that it has ultralow power consumption compared with other similar transistor devices May 19th, 2016