Two-dimensional Ga${}_2$O${}_3$ glass: a large scale passivation and protection material for monolayer WS${}_2$

Abstract

Atomically thin transition metal dichalcogenide crystals (TMDCs) have extraordinary optical properties that make them attractive for future optoelectronic applications. Integration of TMDCs into practical all-dielectric heterostructures hinges on the ability to passivate and protect them against necessary fabrication steps on large scales. Despite its limited scalability, encapsulation of TMDCs in hexagonal boron nitride (hBN) currently has no viable alternative for achieving high performance of the final device. Here, we show that the novel, ultrathin Ga${}_2$O${}_3$ glass is an ideal centimeter-scale coating material that enhances optical performance of the monolayers and protects them against further material deposition. In particular, Ga${}_2$O${}_3$ capping of commercial grade WS${}_2$ monolayers outperforms hBN in both scalability and optical performance at room temperature. These properties make Ga${}_2$O${}_3$ highly suitable for large scale passivation and protection of monolayer TMDCs in functional heterostructures.

References in corpus (12)

• Electric Field Effect in Atomically Thin Carbon Films
• Van der Waals heterostructures
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• The Valley Hall Effect in MoS2 Transistors
• Ultrafast Dynamics of Defect-Assisted Electron-Hole Recombination in Monolayer MoS2
• Evidence of high-temperature exciton condensation in 2D atomic double layers
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Exciton Dynamics in Monolayer Transition Metal Dichalcogenides
• Fundamental Limits of Exciton-Exciton Annihilation for Light Emission in Transition Metal Dichalcogenide Monolayers
• Exciton diffusion in monolayer semiconductors with suppressed disorder
• Zeeman Splitting and Inverted Polarization of Biexciton Emission in Monolayer WS2
• Efficient cathodoluminescence of monolayer transitional metal dichalcogenides in a van der Waals heterostructure