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Scientists have long believed that graphene ribbons are more difficult to manufacture than carbon nanotubes. Graphene is a single-layer carbon atom material stripped from graphite materials. Its thickness is only 0.335 nanometers, and 200,000 sheets of graphene are stacked together. It is only as thick as a hair.
Graphene is highly conductive, slim, transparent and hard, making it ideal for manufacturing displays and solar panels. Banded graphene is more useful. At a width of about 10 nanometers, electrons are forced to move longitudinally, making graphene work like a semiconductor. Semiconductor graphene may be the "gospel" of the electronics industry.
Previously, researchers used chemicals or ultrasound to cut graphene into ribbons, but this method could not be used to make graphene tapes on a large scale, nor to control the width. The research team led by James Nelson, a chemist at Rice University in the United States, and Dai Hongjie, a professor at the Department of Chemistry at Stanford University, used graphene bands to create carbon nanotubes.
Dai Hongjie's research team cut the nanotubes using etching techniques borrowed from the semiconductor industry. They adhered the carbon nanotubes to a polymer film and then etched each strip of each nanotube using ionized argon to obtain a graphene ribbon with a width of only 10 nm to 20 nm.
The James Sai research team used a mixture of potassium permanganate and sulfuric acid to open the nanotubes along an axis, and they got a wider ribbon, about 100 nanometers to 500 nanometers. Although these ribbons are not semiconductors, they are easier to manufacture on a large scale.
The physicist Mao Ruixi Tejonis of the Mexican Institute of Science and Technology believes that these two technologies can complement each other.
James Sai believes that his ribbon can be used to make solar panels, flexible touch screens, and to make thin, conductive fibers to replace the bulky copper wires used on airplanes and spacecraft. Dai Hongjie's narrow band has electrical conductivity and will be widely used in the electronics industry. They have used graphene tape to make basic transistors.
For the first time, scientists have used nanotubes to create graphene strips.
Two groups of scientists in the United States have successfully used cylindrical carbon nanotubes to produce graphene bands of several tens of nanometers wide. The application range of these graphene tapes covers solar cells, computers, and the like. The research was published in the 16th issue of Nature.