LONDON Ė A research team from the Samsung Advanced Institute of Technology (Yongin, Korea) has proposed a novel three-terminal device that could overcome previous problems integrating graphene into circuits. The term barristor comes from running together "variable barrier transistor."
Graphene, an atomic monolayer form of carbon, has attracted much attention because it offers about 200 times higher electron mobility than silicon. However, until recent disclosures about semiconducting graphene monoxide, graphene and its derivatives had only existed as conductors and insulators. The metallic nature of graphene and its high conductivity were accompanied by a lack of hysterisis and no mechanism to switch conduction off.
Converting graphene into a semiconductor can decrease the electron mobility of graphene negating the benefits and leading to skepticism over the feasibility of graphene transistors, Samsung said in a statement.
The team from SAIT, the central R&D arm of Samsung Electronics Co. Ltd., published the paper Graphene Barristor, a Triode Device with a Gate-Controlled Schottky Barrier online in the journal Science on May 17.
The claim is that SAIT has developed a device that can switch off the current in graphene without degrading its mobility. The key is an atomically sharp interface between graphene and hyrogenated silicon. An on/off ratio current modulation of 10^5 is achieved by adjusting the gate voltage to control the graphene-silicon Schottky barrier.
The researchers report the fabrication of complementary p- and n-type graphene barristors as well as inverter and half-adder logic circuits on 150-mm diameter wafers. SAIT said it owns nine major patents related to the structure and the operating method of the graphene barristor.
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