Intrinsic defect engineering of CVD grown monolayer MoS$_2$ for tuneable functional nanodevices
Abstract
Defects in atomically thin materials can drive new functionalities and expand applications to multifunctional systems that are monolithically integrated. An ability to control formation of defects during the synthesis process is an important capability to create practical deployment opportunities. Molybdenum disulfide (MoS), a two-dimensional (2D) semiconducting material harbors intrinsic defects that can be harnessed to achieve tuneable electronic, optoelectronic, and electrochemical devices. However, achieving precise control over defect formation within monolayer MoS, while maintaining the structural integrity of the crystals remains a notable challenge. Here, we present a one-step, in-situ defect engineering approach for monolayer MoS using a pressure dependent chemical vapour deposition (CVD) process. Monolayer MoS grown in low-pressure CVD conditions (LP-MoS) produces sulfur vacancy (Vs) induced defect rich crystals primarily attributed to the kinetics of the growth conditions. Conversely, atmospheric pressure CVD grown MoS (AP-MoS) passivates these Vs defects with oxygen. This disparity in defect profiles profoundly impacts crucial functional properties and device performance. AP-MoS shows a drastically enhanced photoluminescence, which is significantly quenched in LP-MoS attributed to in-gap electron donor states induced by the Vs defects. However, the n-doping induced by the Vs defects in LP-MoS generates enhanced photoresponsivity and detectivity in our fabricated photodetectors compared to the AP-MoS based devices. Defect-rich LP-MoS outperforms AP-MoS as channel layers of field-effect transistors (FETs), as well as electrocatalytic material for hydrogen evolution reaction (HER). This work presents a single-step CVD approach for in-situ defect engineering in monolayer MoS and presents a pathway to control defects in other monolayer material systems.
Keywords
Cite
@article{arxiv.2311.07984,
title = {Intrinsic defect engineering of CVD grown monolayer MoS$_2$ for tuneable functional nanodevices},
author = {Irfan H. Abidi and Sindhu Priya Giridhar and Jonathan O. Tollerud and Jake Limb and Aishani Mazumder and Edwin LH Mayes and Billy J. Murdoch and Chenglong Xu and Ankit Bhoriya and Abhishek Ranjan and Taimur Ahmed and Yongxiang Li and Jeffrey A. Davis and Cameron L. Bentley and Salvy P. Russo and Enrico Della Gaspera and Sumeet Walia},
journal= {arXiv preprint arXiv:2311.07984},
year = {2023}
}
Comments
29 pages, 5 figures