Graphene-carbon nanotubes promise cheaper, more powerful electronic devices

Washington, May 14 (ANI): Scientists at the University of California-Los Angeles (UCLA) say that they have devised a novel way to make a hybrid graphene-carbon nanotube (G-CNT), which can be used as a transparent conductor in solar cells and consumer electronic devices.

Lead researchers Yang Yang and Richard Kaner reckon that G-CNTs may provide a cheaper and much more flexible alternative to materials currently used in these and similar applications.

Presently, the creation of transparent conductors depends upon indium tin oxide (ITO), which is expensive because of its production costs and a relative scarcity of indium.

The researchers say that the G-CNT hybrid provides an ideal high-performance alternative to ITO in electronics with moving parts.

They point out that graphene is an excellent electrical conductor, and carbon nanotubes are good candidates for transparent conductors because they provide conduction of electricity using very little material.

Yang and Kaner say that their single-step technique to combine the two is easy, inexpensive, scalable and compatible with flexible applications.

According to them, G-CNTs produced this way already provide comparable performance to current ITOs used in flexible applications.

The researchers have revealed that their method builds on one of their previous studies, which introduced a method for producing graphene, a single layer of carbon atoms, by soaking graphite oxide in a hydrazine solution.

They have now found that placing both graphite oxide and carbon nanotubes in a hydrazine solution produces not only graphene but a hybrid layer of graphene and carbon nanotubes.

"To our knowledge this is the first report of dispersing CNTs in anhydrous hydrazine. This is important because our method does not require the use of surfactants, which have traditionally been used in these solution processes and can degrade intrinsic electronic and mechanical properties," Yang said.

G-CNTs are also ideal candidates for use as electrodes in polymer solar cells because they retain efficiency when flexed and also are compatible with plastics.

The researcher envision the use of such flexible solar cells in a variety of materials, including the drapes of homes.

"The potential of this material (G-CNT) is not limited to improvements in the physical arrangements of the components. With further work, G-CNTs have the potential to provide the building blocks of tomorrow's optical electronics," said Vincent Tung, a doctoral student working jointly in Yang's and Kaner's labs and the first author of the study.

The novel processing method has been described in a research paper published in the journal Nano Letters. (ANI)