UCLA - Page 2

Update: Check out this short video explaining this new research and showing the people behind it, and the next-gen technique unveiled in February 2013

A team of researchers from the UCLA managed to developed laser-scribed graphene (LSG) based flexible capacitors using simple DVD burners. The idea is to deposit Graphite Oxide on blank DVDs and then use a DVD burner (a light scribe drive) which uses a 780nm infrared laser. The laser reduces the Graphite Oxide to pure graphene (LSG). This LSG is placed on flexible substrates which are used as the electrodes for a super capacitor.

This is not just a gimmick process - it will be possible to scale it for commercial production, and these capacitors are fast (20 times faster than standard carbon capacitors and 3 times faster than lithium-ion batteries) and offer good density (twice than that of carbon capacitors and comparable to a high-power lithium-ion battery).

A research team from UCLA announce they have developed a scalable approach to fabricate high-speed graphene transistors. Back in September 2010, this team developed 300Ghz graphene transistors, making them using a nanowire as the self-aligned gate.

The new approach uses a dielectrophoresis assembly approach to precisely place nanowire gate arrays on large-area chemical vapor depositiongrowth graphene (as opposed to mechanically peeled graphene flakes) to enable the rational fabrication of high-speed transistor arrays. This was made on a glass substrate. The new transistors have cut-off frequencies of over 50Ghz (typical graphene transistors made on silicon have cut-off frequencies of less then 10 Ghz).

Researchers from UCLA says they have developed a new Graphene transistor - running at 300Ghz - the fastest to date. The team, led by professor of chemistry and biochemistry Xiangfeng Duan, has developed a new fabrication process for graphene transistors using a nanowire as the self-aligned gate.

Researchers from UCLA has created a new Graphene nanostructure called Graphene nanomesh (GNM). The new structure is able to open up a band gap in a large sheet of graphene to create a highly uniform, continuous semiconducting thin film that may be processed using standard planar semiconductor processing methods.

The nanomesh can have variable periodicities, defined as the distance between the centers of two neighboring nanoholes. Neck widths, the shortest distance between the edges of two neighboring holes, can be as low as 5 nanometers. This ability to control nanomesh periodicity and neck width is very important for controlling electronic properties because charge transport properties are highly dependent on the width and the number of critical current pathways.