Research:  Carbon Nanotube Devices & Circuits

 

Excitonic FET - A Novel, Steep-Slope Alternative

Similar to the tunneling field-effect transistor (TFET), the excitonic FET (ExFET) aims to provide a low-subthreshold-swing option to overcome the 60mV/decade minimum requirement inherent in conventional CMOS-based electronics, thereby alleviating power dissipation problems in future nanoelectronics. In this steep-slope alternative, we propose that coulomb interaction between electrons and holes in parallel n- and p-type channels can enable exciton binding under certain gate bias conditions. When the conditions for formation of a collective excitonic condensate are satisfied the channel current transitions from a conductive ON-state to a nonconductive OFF-state, yielding an abrupt subthreshold swing.

We are experimentally exploring the necessary conditions to access the exciton condensate in spatially separated low-dimensional structures, such as carbon nanotubes. Specifically, we are modifying the spatial separation of the channels and side-gate bias conditions to realize the abrupt change between the ‘exciton condensate state’ and the normal ‘single particle state’.