Moiré Exciton Polaron Engineering via twisted hBN

Abstract

Twisted hexagonal boron nitride (thBN) exhibits ferroelectricity due to moiré superlattices with AB/BA domains. These domains possess electric dipoles, leading to a periodic electrostatic potential that can be imprinted onto other materials placed in its proximity. Here we demonstrate the remote imprinting of moiré patterns from thBN onto monolayer MoSe₂ and investigate the changes in the exciton properties. We confirm the imprinted moiré patterns on monolayer MoSe₂ using Kelvin probe force microscopy (KPFM) and hyperspectral photoluminescence (PL) mapping. By creating a large ferroelectric domain (∼8.7 μm), we achieve unprecedented potential modulation (∼387 ± 52 meV). We observe the formation of exciton-polarons by the ferroelectric moiré domains and investigate the optical property changes induced by the moiré pattern in monolayer MoSe₂ by varying the moiré domain size down to ∼110 nm. Our findings highlight the potential of thBN as a platform for controlling the properties of 2D materials for optoelectronic and valleytronic applications.