Silicon-free computer circuits
The EU's NICE project is investigating the potential of fullerene-based technologies as alternatives to silicon devices. Fullerenes are large carbon-cage molecules, with the ability to enclose other atoms within their hollow cage structures. Such compounds are termed endohedral fullerenes and they exhibit a number of non-carbon-like properties. One of these properties is the ability to superconduct at relatively high temperatures. The NICE project put the properties of the endohedral fullerenes to the test with the aim of combining such materials with nano-computing technologies to arrive at novel integrated circuits. One of the major obstacles to this line of research, however, has been the difficulty associated with the isolation and purification of endohedral fullerenes. To address this issue, a new high performance liquid chromatography method was developed at the University of Göteborg. A series of complex chemical steps, which resulted in the final highly purified molecules, were shown to be highly effective for the C60 carbon fullerenes. Fullerenes of higher carbon content proved more challenging to purify. The production of endohedral fullerenes at first instance can be achieved through the use of low energy implantation sources. The technique was optimised for the implantation of Li, K and Na atoms inside the hollow spaces of fullerenes. Overall, the project has managed to devise optimum conditions for the production of endohedral fullerenes and also yield highly purified fullerene material through a series of chromatographic steps. The knowledge gained so far is key to the further application of fullerenes for the manufacture of integrated circuits, independent of silicon.
