Operating Principles of Vertical Transistors Based on Monolayer Two-Dimensional Semiconductor Heterojunctions

TL;DR

This paper theoretically investigates a double-gated, atomically thin heterojunction vertical transistor, demonstrating its potential for efficient switching, high saturation, and tunable band alignment, advancing 2D semiconductor device understanding.

Contribution

It introduces a novel theoretical analysis of a double-gated monolayer heterojunction vertical transistor with tunable band alignment and enhanced switching characteristics.

Findings

Excellent saturation of output I-V characteristics.

Subthreshold slope below thermionic limit due to band filtering.

Electrostatic modulation from type II to broken bandgap alignment.

Abstract

A vertical transistor based on a double gated, atomically thin heterojunction is theoretically examined. Both p-type and n-type transistor operations can be conveniently achieved by using one of the two gates as the switching gate. The transistor shows excellent saturation of output I-V characteristics due to drain-induced depletion and lack of tunneling barrier layers. The subthreshold slope could be below the thermionic limit due to band filtering as the switching mechanism. The atomically thin vertical PN heterojunction can be electrostatically modulated from a type II heterojunction to a broken bandgap alignment, which is preferred for maximizing the on-current.