Dielectric engineering enable to lateral anti-ambipolar MoTe2heterojunction

Abstract

Atomically two-dimensional (2D) materials have generated widespread interest for novel electronics and optoelectronics. Specially, owing to atomically thin 2D structure, the electronic bandgap of 2D semiconductors can be engineered by manipulating the surrounding dielectric environment. In this work, we develop an effective and controllable approach to manipulate dielectric properties of h-BN through gallium ions (Ga⁺) implantation for the first time. And the maximum surface potential difference between the intrinsic h-BN (h-BN) and the Ga⁺implanted h-BN (Ga⁺-h-BN) is up to 1.3 V, which is characterized by Kelvin probe force microscopy. More importantly, the MoTe₂transistor stacked on Ga⁺-h-BN exhibits p-type dominated transfer characteristic, while the MoTe₂transistor stacked on the intrinsic h-BN behaves as n-type, which enable to construct MoTe₂heterojunction through dielectric engineering of h-BN. The dielectric engineering also provides good spatial selectivity and allows to build MoTe₂heterojunction based on a single MoTe₂flake. The developed MoTe₂heterojunction shows stable anti-ambipolar behaviour. Furthermore, we preliminarily implemented a ternary inverter based on anti-ambipolar MoTe₂heterojunction. Ga⁺implantation assisted dielectric engineering provides an effective and generic approach to modulate electric bandgap for a wide variety of 2D materials. And the implementation of ternary inverter based on anti-ambipolar transistor could lead to new energy-efficient logical circuit and system designs in semiconductors.

Keywords: FIB; KPFM; MoTe2; anti-ambipolar; dielectric engineering; h-BN; ternary inverter.