Near- and Far-Field Observation of Phonon Polaritons in Wafer Scale Multilayer Hexagonal Boron Nitride Prepared by Chemical Vapor Deposition.

Polaritons in layered materials (LMs) are a promising platform to manipulate and control light at the nanometer scale. Thus, the observation of polaritons in wafer-scale LMs is critically important for the development of industrially relevant nanophotonics and optoelectronics applications. Here w e report phonon polaritons (PhPs) in wafer-scale multilayer hexagonal boron nitride (hBN) grown by chemical vapor deposition. By infrared nanoimaging w e visualize the PhPs and measure their lifetime of about 0.6 ps, comparable to that of micromechanically exfoliated multilayer hBN. W e also demonstrate PhP nano-resonators with quality factors of about 50, which is 0.7 times that of state of-the-art devices based on exfoliated hBN. O ur results could enable PhP-based surface-enhanced infrared spectroscopy (e.g., for gas sensing) and infrared photodetector applications. This article is protected by copyright. All rights reserved.