Findings were detailed in a paper, "Complementary-Type Graphene Inverters Operating at Room-Temperature," presented in June during the 2011 Device Research Conference in Santa Barbara, Calif.
Thus far graphene transistors have been practical only for specialized applications, such as amplifiers for cell phones and military systems. However, the new inverters represent a step toward learning how to use the material to create graphene transistors for broader digital applications that include computers and consumer electronics.
To create electronic devices, silicon is impregnated with impurities to change its semiconducting properties. Such "doping" is not easily applicable to graphene. However, the researchers have potentially solved this problem by developing "electrostatic doping," which makes it possible for graphene inverters to mimic the characteristics of silicon inverters.
Electrostatic doping is induced through the electric field between metal gates, which are located 40 nanometers away from graphene channels. The doping can be altered by varying the voltage, enabling researchers to test specific doping levels.
"This will allow us to find the sweet spot for operating the device," Chen said.
Further work will be needed to integrate the prototype into a working graphene circuit for digital applications.
|Contact: Emil Venere|