Chemically Tailored Growth of 2D Semiconductors via Hybrid Metal-Organic Chemical Vapor Deposition

TL;DR

This paper introduces a hybrid MOCVD method combining liquid and vapor-phase precursors for growing high-quality 2D TMDCs like WS₂ with tunable properties, enabling controlled doping and heterostructure formation.

Contribution

The study develops a hybrid growth technique that enhances control over 2D TMDC synthesis, including doping and heterostructure fabrication, surpassing existing methods in versatility and quality.

Findings

Achieved WS₂ monolayer films with narrow PL linewidths down to 33 meV.

Demonstrated room-temperature mobility of 34-36 cm²V⁻¹s⁻¹.

Successfully grew doped and heterostructured TMDCs with simple precursor modifications.

Abstract

Two-dimensional (2D) semiconducting transition-metal dichalcogenides (TMDCs) are an exciting platform for new excitonic physics and next-generation electronics, creating a strong demand to understand their growth, doping, and heterostructures. Despite significant progress in solid-source (SS-) and metal-organic chemical vapor deposition (MOCVD), further optimization is necessary to grow highly crystalline 2D TMDCs with controlled doping. Here, we report a hybrid MOCVD growth method that combines liquid-phase metal precursor deposition and vapor-phase organo-chalcogen delivery to leverage the advantages of both MOCVD and SS-CVD. Using our hybrid approach, we demonstrate WS$_2$ growth with tunable morphologies - from separated single-crystal domains to continuous monolayer films - on a variety of substrates, including sapphire, SiO$_2$, and Au. These WS$_2$ films exhibit narrow neutral exciton photoluminescence linewidths down to 33 meV and room-temperature mobility up to 34 - 36 cm$^2$V$^-$$^1$s$^-$$^1$). Through simple modifications to the liquid precursor composition, we demonstrate the growth of V-doped WS$_2$, MoxW$_1$$_-$$_x$S$_2$ alloys, and in-plane WS$_2$-MoS$_2$ heterostructures. This work presents an efficient approach for addressing a variety of TMDC synthesis needs on a laboratory scale.