The Adatom Concentration Profile : A Paradigm for Understanding Two-Dimensional MoSMorphological Evolution in Chemical Vapor Deposition Growth

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

1 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)6839–6848
Journal / PublicationACS Nano
Volume15
Issue number4
Online published22 Mar 2021
Publication statusPublished - 27 Apr 2021

Abstract

The two-dimensional (2D) transition metal dichalcogenide (TMD) MoS2 possesses many intriguing electronic and optical properties. Potential technological applications have focused much attention on tuning MoS2 properties through control of its morphologies during growth. In this paper, we present a unified spatial-temporal model for the growth of MoS2 crystals with a full spectrum of shapes from triangles, concave triangles, three-point stars, to dendrites through the concept of the adatom concentration profile (ACP). We perform a series of chemical vapor deposition (CVD) experiments controlling adatom concentration on the substrate and growth temperature and present a method for experimentally measuring the ACP in the vicinity of growing islands. We apply a phase-field model of growth that explicitly considers similar variables (adatom concentration, adatom diffusion, and noise effects) and cross-validate the simulations and experiments through the ACP and island morphologies as a function of physically controllable variables. Our calculations reproduce the experimental observations with high fidelity. The ACP is an alternative paradigm to conceptualize the growth of crystals through time, which is expected to be instrumental in guiding the rational shape engineering of MoS2 crystals.

Research Area(s)

  • chemical vapor deposition, morphology engineering, MoS2, MoS2dendrite, phase-field simulation