Graphene is a sheet form of carbon one atom thick with high electron mobility and the scientists have developed a scalable and inexpensive process for the creation of microelectronic and optoelectronic devices. Graphene's high conductivity and transparency make it a candidate as a transparent, conductive electrode to replace the relatively brittle and expensive indium tin oxide (ITO) in applications such as solar cells, organic light emitting diodes (OLEDs), flat panel displays, and touch screens.
The scientists built the graphene devices on substrates of soda-lime glass – the most common glass used in bottles and windows – and found that the sodium present in the glass could act as dopant for the graphene. The effect remained strong in the devices even after they had been exposed to air for several weeks.
A scanning electron micrograph of the device as seen from above, with the white scale bar measuring 10 microns, and a transmission electron micrograph inset of the CIGS/graphene interface where the white scale bar measures 100 nanometers. Source Brookhaven National Laboratory.
"The sodium inside the soda-lime glass creates high electron density in the graphene, which is essential to many processes and has been challenging to achieve," said Nanditha Dissanayake of Voxtel, Inc., but formerly of Brookhaven Lab and one of the journal Scientific Reports.