Anisotropic index of refraction and structural properties of hexagonal boron nitride epilayers probed by spectroscopic ellipsometry
- 7 February 2020
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 127 (5), 053103
- https://doi.org/10.1063/1.5134908
Abstract
The anisotropic index of refraction of 200 mu m thick boron-10 enriched hexagonal boron nitride (h-BN) freestanding epilayers grown by metalorganic chemical vapor deposition has been measured using spectroscopic ellipsometry in the UV (4.0-5.1 eV) spectral range. It was found that the index of refraction for the polarization mode with an electric field perpendicular to the c-axis (ordinary, n(o)) is much higher than that with an electric field parallel to the c-axis (extraordinary, n(e)). By inclusion of turbostratic- (t-) phase layers within h-BN having an average inclination angle (theta) with respect to the ideal c-plane, a simple method for quantifying theta has been deduced. Our results revealed that the presence of t-phase layers decreases the optical anisotropy of h-BN and that a signature of improved crystalline quality is an increase in the ordinary index of refraction (n(o)) as a result of the average incline angle theta approaching 0 degrees and predicted that n(o) = 2.7 and n(e) = 1.5 at 280 nm for single crystalline h-BN epilayers. More importantly, our results demonstrated that spectroscopic ellipsometry is an effective technique for characterizing the crystalline quality of h-BN epilayers with the advantages of being noninvasive and highly sensitive.Funding Information
- Advanced Research Projects Agency - Energy (DEAR0000964)
This publication has 53 references indexed in Scilit:
- Bandgap and exciton binding energies of hexagonal boron nitride probed by photocurrent excitation spectroscopyApplied Physics Letters, 2016
- Two-dimensional excitons in three-dimensional hexagonal boron nitrideApplied Physics Letters, 2013
- Arnaud, Lebègue, Rabiller, and Alouani Reply:Physical Review Letters, 2008
- Comment on “Huge Excitonic Effects in Layered Hexagonal Boron Nitride”Physical Review Letters, 2008
- Deep Ultraviolet Light-Emitting Hexagonal Boron Nitride Synthesized at Atmospheric PressureScience, 2007
- Excitons in Boron Nitride Nanotubes: Dimensionality EffectsPhysical Review Letters, 2006
- Huge Excitonic Effects in Layered Hexagonal Boron NitridePhysical Review Letters, 2006
- Direct-bandgap properties and evidence for ultraviolet lasing of hexagonal boron nitride single crystalNature Materials, 2004
- Characterization and Field Emission of Sulfur-Doped Boron Nitride Synthesized by Plasma-Assisted Chemical Vapor DepositionJapanese Journal of Applied Physics, 1997
- Boron nitride coatings of steel and graphite produced with a low pressure r.f. plasmaThin Solid Films, 1980