Reconfigurable Mixed-Dimensional Transistor With Semimetal CNT Contacts

Abstract

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.