Remote Exciton Polaron Engineering via twisted hBN

Minhyun Cho
Kyung Hee University, Seoul, Republic of Korea _______________________________________

Twisted hexagonal boron nitride (thBN) exhibits emergent ferroelectricity due to the formation of moiré 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 report the remote engineering of exciton polarons in monolayer MoSe₂ through proximity coupling to a twisted hexagonal boron nitride (thBN) substrate. We confirm the imprinting of moiré 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, we achieve unprecedented potential modulation. We observe the formation of exciton polarons due to charge redistribution caused by the ferroelectric moiré domains and investigate the optical property changes induced by the moiré pattern in monolayer MoSe₂ by varying the moiré pattern size. 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.

Email: cho@khu.ac.kr