A facile direct device transfer of monolayer MoS2 towards improvement in transistor performances

TL;DR

This paper presents a simple, etching-free transfer method for monolayer MoS2 and metal electrodes, resulting in high-quality, high-performance transistors with improved electrical properties suitable for large-scale electronic applications.

Contribution

A novel direct device transfer technique that simplifies the process and enhances the performance of MoS2 transistors by preserving material quality and interface integrity.

Findings

Residue-free monolayer MoS2 transfer achieved

Enhanced transistor performance with reduced hysteresis

Improved mobility and Schottky barrier characteristics

Abstract

Transfer techniques based on two dimensional (2D) materials and devices offer immense potential towards their industrial integration with the existing silicon based electronics. To achieve high quality devices, there is an urgent requirement for the etching-free, and clean transfer that retain original semiconducting properties of layered channel materials. In parallel, transfer of metal electrode arrays on the 2D semiconductors also attract attention towards large-scale integration for commercial applications. Here, we demonstrate a facile PMMA-assisted etching-free one-step approach to transfer both 2D channels and metal electrodes without damaging the contact region. The direct device transfer (DDT) technique enables residue-free monolayer MoS2 as channel material towards achieving doping-free intrinsic transistors with enhanced performances. The crystalline quality, strain relaxation, and interfacial coupling effects are studied using Raman and photoluminescence spectra with spatial mapping. Post device transfer, a reduced pinning effect is observed by the effective modulation of gate tunable drain currents in MoS2 transistors at room temperature. Furthermore, the extracted Schottky barrier heights, temperature dependence of threshold voltage shifts, hysteresis evolution, and mobility enhancements validates the improved transistor performances in transferred devices. The proposed DDT method can be utilized to directly transfer array of devices of 2D materials and heterostructures skipping various cumbersome steps in between and hence could offer high performance reliable electronic applications.