Moir\'e exciton polaron engineering via twisted hBN

TL;DR

This study demonstrates remote moiré pattern imprinting from twisted hBN onto monolayer MoSe2, enabling control over exciton properties and exciton polaron formation through engineered ferroelectric domains for advanced 2D material applications.

Contribution

It introduces a method to imprint large ferroelectric moiré patterns onto 2D materials and investigates their impact on exciton and polaron properties, advancing 2D heterostructure engineering.

Findings

Successful imprinting of moiré patterns onto MoSe2 confirmed by microscopy.

Achieved potential modulation of approximately 387 meV.

Observed exciton polaron formation due to charge redistribution.

Abstract

Twisted hexagonal boron nitride (thBN) exhibits emergent ferroelectricity due to the formation of moir\'e superlattices with alternating AB and BA domains. These domains possess electric dipoles, leading to a periodic electrostatic potential that can be imprinted onto other 2D materials placed in its proximity. Here we demonstrate the remote imprinting of moir\'e patterns from twisted hexagonal boron nitride (thBN) onto monolayer MoSe2 and investigate the resulting changes in the exciton properties. We confirm the imprinting of moir\'e patterns on monolayer MoSe2 via proximity using Kelvin probe force microscopy (KPFM) and hyperspectral photoluminescence (PL) mapping. By developing a technique to create large ferroelectric domain sizes ranging from 1 {\mu}m to 8.7 {\mu}m, we achieve unprecedented potential modulation of 387 +- 52 meV. We observe the formation of exciton polarons due to charge redistribution caused by the antiferroelectric moir\'e domains and investigate the optical property changes induced by the moir\'e pattern in monolayer MoSe2 by varying the moir\'e pattern size down to 110 nm. Our findings highlight the potential of twisted hBN as a platform for controlling the optical and electronic properties of 2D materials for optoelectronic and valleytronic applications.