Light emission by individual defects in 2D materials

Abstract

In this project we aim to study individual defects in bi-dimensional nanostructures and their electronic and optical properties. Indeed, point defects (vacancies, substitutional atoms and associations) have profound effects in the luminescence of hexagonal Boron Nitride (hBN) and on transition-metal chalcogenides (TMDs), like MoS2 e WSe2. In this materials, punctual defects can be used as Single Photon Emitters (SPEs), can increase their quantum efficiency or change their light emission energies. Despite all technological and scientific interest, many open question remains about the role of each particular defect or how to control their density to achieve desired properties. With this aim, we plan to prepare defects in a controlled fashion using low energy ion beams (~150 eV) and to study their morphology, electronic structure and light emission by using high resolution microscopy adapted to optical studies which are Cathodoluminescence in Scanning Transmission Electronic Microscopy and luminescence in Scanning Tunneling microscopy. This methodology will contribute to the advance in the understanding of individual defect in this knowledge frontier. (AU)