sSNOM characterization of the IR-active vibrational mode in highly strained hBN
28 Aug 2022-pp 1-2
TL;DR: In this article , a sSNOM experiment on micrometric-sized bubbles of hBN with the aim of addressing the response to strain of the transverse optical IR-active mode is presented.
Abstract: Hexagonal Boron Nitride is a layered insulator often employed as a protective layer for heterostructures or as host for single photon emitters. In particular, the emission of defects in hBN can be tuned by strain, and it is therefore of the utmost importance to have a reliable method to quantify strain in this system. Here we present a sSNOM experiment on micrometric-sized bubbles of hBN with the aim of addressing the response to strain of the transverse optical IR-active mode.
TL;DR: In this article , a technique based on hydrogen irradiation was proposed to induce the formation of wrinkles and bubbles in hexagonal boron nitride (hBN), resulting in remarkably high strains of ∼2%.
Abstract: Hexagonal boron nitride (hBN) is widely used as a protective layer for few-atom-thick crystals and heterostructures (HSs), and it hosts quantum emitters working up to room temperature. In both instances, strain is expected to play an important role, either as an unavoidable presence in the HS fabrication or as a tool to tune the quantum emitter electronic properties. Addressing the role of strain and exploiting its tuning potentiality require the development of efficient methods to control it and of reliable tools to quantify it. Here we present a technique based on hydrogen irradiation to induce the formation of wrinkles and bubbles in hBN, resulting in remarkably high strains of ∼2%. By combining infrared (IR) near-field scanning optical microscopy and micro-Raman measurements with numerical calculations, we characterize the response to strain for both IR-active and Raman-active modes, revealing the potential of the vibrational properties of hBN as highly sensitive strain probes.