Doping Concentration Modulation in Vanadium Doped Monolayer Molybdenum Disulfide for Synaptic Transistors

TL;DR

This paper demonstrates a method for wide-range, uniform vanadium doping in monolayer MoS2 via chemical vapor deposition, enabling the fabrication of synaptic transistors that mimic neural processes through gate-tunable conductance.

Contribution

It introduces a scalable in-situ doping technique for monolayer MoS2 with tunable vanadium concentrations and applies it to create artificial synaptic transistors.

Findings

Achieved doping concentrations from 0.3 to 13.1 at%.

Demonstrated gate-tunable conductance for synaptic functions.

Enabled large-scale uniform doping of 2D MoS2.

Abstract

Doping is an effective way to modify the electronic property of two-dimensional (2D) materials and endow them with new functionalities. However, wide-range control of the substitutional doping concentration with large scale uniformity remains challenging in 2D materials. Here we report in-situ chemical vapor deposition growth of vanadium (V) doped monolayer molybdenum disulfide (MoS2) with widely tunable doping concentrations ranging from 0.3 to 13.1 at%. The key to regulate the doping concentration lies in the use of appropriate V precursors with different doping abilities, which also generate a large-scale uniform doping effect. Artificial synaptic transistors were fabricated by using the heavily doped MoS2 as the channel material for the first time. Synaptic potentiation, depression and repetitive learning processes are mimicked by the gate-tunable channel conductance change in such transistors with abundant V atoms to trap/detrap electrons. This work shows a feasible method to dope monolayer 2D semiconductors and demonstrates their use in artificial synaptic transistors.