Abstract
Phonon polaritons (PhPs) enable a variety of applications, yet it requires PhPs supported in the desired frequency range. The two BN allotropes (cubic and hexagonal, cBN and hBN) are of particular interest, as their optic phonons fall within the so-called molecular-fingerprint region (~ 1000–1610 cm−1). However, there remains a spectral gap between PhPs covered by these two, limiting applications. Thus, we isotopically engineered hBN and cBN and examined the optic phonons. For hBN, enhancement of the optic phonon lifetimes and shifted frequencies are observed. However, lifetimes are observed to decrease with the enrichment of cBN by 10B, 11B, and 15N. We propose that the reduced lifetimes are not due to intrinsic loss, but rather increased defect concentrations resulting from the modified growth, supported by first-principles calculations. Thus, reducing the extrinsic defects in isotopically engineered cBN may present a path toward overcoming these restrictions for applications in the molecular-fingerprint region. Graphical abstract: [Figure not available: see fulltext.].
| Original language | English |
|---|---|
| Pages (from-to) | 4394-4403 |
| Number of pages | 10 |
| Journal | Journal of Materials Research |
| Volume | 36 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 14 2021 |
Funding
M. H. and J. D. C. gratefully acknowledge support for this work by Office of Naval Research Grant N00014-18-12107. L. L. acknowledges support for theory and numerical calculations from the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Material Sciences and Engineering Division. J. M. was supported by the National Science Foundation, Division of Materials Research under grant number 1904793. Computational resources were provided by the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231. A. McDonald is recognized for his work in supporting Raman spectroscopy efforts. This work was undertaken, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the US DOE’s National Nuclear Security Administration under Contract No. DE-NA-0003525. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan, Grant Number JPMXP0112101001 and Grant Number JP20H00354. T.G.F. was supported by Vanderbilt University through J. D. C’s startup package.
| Funders | Funder number |
|---|---|
| National Science Foundation | |
| Office of Naval Research | N00014-18-12107 |
| U.S. Department of Energy | |
| Division of Materials Research | 1904793 |
| Office of Science | DE-AC02-05CH11231 |
| Basic Energy Sciences | |
| National Nuclear Security Administration | DE-NA-0003525 |
| Vanderbilt University | |
| Ministry of Education, Culture, Sports, Science and Technology | JP20H00354, JPMXP0112101001 |