Enhanced On-state Current in Barrier-free Carbon Heterojunction Tunneling Field-effect Transistor

It has been experimentally shown that metallic zigzag graphene nanoribbon (ZGNR) can be obtained by unzipping a carbon nanotube (CNT) along the chiral direction of CNT. This makes it possible to fabricate a unique AGNR-ZGNR-CNT heterojunction so that the semi-metallic ZGNR is between semiconducting AGNR and CNT. Here we demonstrate that such a unique all-carbon heterojunction may be utilized to obtain a barrier-free tunneling field-effect transistor (TFET). By performing a self-consistent first-principle calculation based on density functional theory combined with none-equilibrium Green's function (DFT-NEGF), we show that such a barrier-free TFET may reduce subthreshold swing below the classical limit while increase on-state current by diminishing tunneling barrier, which provides an promising route toward ultralow-power, highperformance carbon heterojunction electronics.