Presentation
1 August 2021 Deep-UV reflectivity in hexagonal boron nitride: from monolayer to bulk samples
Author Affiliations +
Abstract
Hexagonal boron nitride (hBN) is an ultrawide bandgap semiconductor with a large range of basic applications relying on its low dielectric constant, high thermal conductivity, and chemical inertness. The growth of high-quality crystals in 2004 has revealed that hBN is also a promising material for light-emitting devices in the deep ultraviolet domain, as illustrated by the demonstration of lasing at 215 nm by accelerated electron excitation [1], and also the operation of field emitter display-type devices in the deep ultraviolet [2]. With a honeycomb structure similar to graphene, bulk hBN has gained tremendous attention as an exceptional substrate for graphene with an atomically smooth surface, and more generally, as a fundamental building block of Van der Waals heterostructures [3]. I will discuss here our recent measurements by reflectivity spectroscopy shining a new light on the efficient light-matter interaction in hBN. I will first present experiments in monolayer hBN epitaxially grown on graphite. Compared to the reflectivity spectrum of the bare graphite substrate, a huge contrast is observed in the reflectivity of atomically-thin hBN deposited on graphite, demonstrating a radiative efficiency close to unity in monolayer hBN. I will then address the optoelectronic properties of bulk hBN where high-resolution measurements in high-quality samples allow to resolve the respective contributions of indirect and direct optical transitions and quantify the strength of the light-matter interaction in bulk hBN. References [1] K. Watanabe, T. Taniguchi, and H. Kanda, Nature Mater. 3, 404 (2004). [2] K. Watanabe, T. Taniguchi, T. Niiyama, K. Miya, and M. Taniguchi, Nature Photon. 3, 591 (2009). [3] A. K. Geim and I. V. Grigorieva, Nature 499, 419 (2013).
Conference Presentation
© (2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Guillaume Cassabois "Deep-UV reflectivity in hexagonal boron nitride: from monolayer to bulk samples", Proc. SPIE 11801, UV and Higher Energy Photonics: From Materials to Applications 2021, 118010D (1 August 2021); https://doi.org/10.1117/12.2593931
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KEYWORDS
Reflectivity

Deep ultraviolet

Boron

Graphene

Light-matter interactions

Reflectance spectroscopy

Heterojunctions

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