Van der Waals stack amplifies weak quantum signals in 2D materials

Researchers have achieved up to a 45-fold increase in the photoluminescence of boron vacancies in hexagonal boron nitride at 4 Kelvin using a novel van der Waals heterostructure. The work demonstrates a mechanism where light absorbed by lead iodide drives excitation of the boron vacancy defect, boosting signal strength without compromising its spin properties. This coupling, enabled by a type-I band alignment at the lead iodide-hBN interface, facilitates efficient energy transfer and improved sensitivity to external magnetic fields, establishing a route for amplifying weak quantum defect signals in nanomaterials. This stacked structure, comprised of hexagonal boron nitride, a boron vacancy layer, and lead(II) iodide, uses a mechanism to amplify the typically weak signal emitted by the boron vacancies without compromising their spin properties. The design relies on the efficient transfer of energy from the lead iodide to the boron vacancy, effectively increasing the…