Reconfigurable Mixed-Dimensional Transistor With Semimetal CNT Contacts

Reconfigurable low-dimensional devices are attractive for electronics in the post-Moore era. However, their performance and function design are limited by the metal-semiconductor contacts for the Fermi level pinning and fixed Schottky barrier height (SBH). Here, semimetal carbon nanotube (sCNT) contacts are incorporated into a WSe2 transistor to address these issues. The transistor exhibits excellent ambipolar transfer characteristics with on/off ratio exceeding 107 for both hole and electron conduction. Furthermore, the output characteristics are reconfigured among the four equivalent modes, P-P, P-N, N-P, and N-N, by applying appropriate gate voltage. The significant forward and backward rectifying behaviors at P-N and N-P modes are highly symmetrical and have high rectification ratios of over 106. The improvements are attributed to specific semimetal contacts for the gate-tunable SBH and the drain-induced Schottky barrier lowering (DISBL) effect. Practical circuits include a reconfigurable filter circuit and a logic invertor have been further demonstrated successfully. The progress reveals that the semimetal contacts have great potential in future reconfigurable devices and circuits.