@article{e830fb00cd7144399a7eddcf3ea45ff1,
title = "Phonon Lifetimes in Boron-Isotope-Enriched Graphene- Hexagonal Boron Nitride Devices",
abstract = "Using hexagonal boron nitride (hBN) as a substrate for graphene has shown faster carrier cooling which makes it ideal for high-power graphene-based devices. However, the effect of using boron-isotope-enriched hBN has not been explored. Herein, femtosecond pump-probe spectroscopy is utilized to measure and compare the time dynamics of photo-excited carriers in graphene-hBN heterostructures for hBN with the natural distribution of boron isotopes (20% 10B and 80% 11B) and hBN enriched to 100% 10B and 11B. The carriers cool down faster for systems with isotopically pure hBN substrates by a factor of ≈1.7 times. This difference in relaxation times arises from the interfacial coupling between carriers in graphene and the hBN phonon modes. The results show that the boron isotopic purity of the hBN substrate can help to reduce the hot phonon bottleneck that limits the cooling in graphene devices.",
keywords = "2D heterostructures, carrier cooling, conductance, graphene, hBN, phonons",
author = "Alexandra Brasington and Song Liu and Takashi Taniguchi and Kenji Watanabe and Edgar, {James H.} and LeRoy, {Brian J.} and Arvinder Sandhu",
note = "Funding Information: This work is supported at the University of Arizona by the Army Research Office under Grant nos. W911NF‐14‐1‐0653 and W911NF‐20‐1‐0215, and by the National Science Foundation under award nos. 1912455 and 1919486. S.L. and J.E. acknowledge support for the isotopically enriched hBN crystal growth from the Materials Engineering and Processing program of the National Science Foundation, award number CMMI 1538127, and the II−VI Foundation. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan (Grant Number JPMXP0112101001) and JSPS KAKENHI (Grant Numbers 19H05790, 20H00354, and 21H05233). Funding Information: This work is supported at the University of Arizona by the Army Research Office under Grant nos. W911NF-14-1-0653 and W911NF-20-1-0215, and by the National Science Foundation under award nos. 1912455 and 1919486. S.L. and J.E. acknowledge support for the isotopically enriched hBN crystal growth from the Materials Engineering and Processing program of the National Science Foundation, award number CMMI 1538127, and the II−VI Foundation. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan (Grant Number JPMXP0112101001) and JSPS KAKENHI (Grant Numbers 19H05790, 20H00354, and 21H05233). Publisher Copyright: {\textcopyright} 2022 Wiley-VCH GmbH.",
year = "2022",
month = jun,
doi = "10.1002/pssr.202200030",
language = "English (US)",
volume = "16",
journal = "Physica Status Solidi - Rapid Research Letters",
issn = "1862-6254",
publisher = "Wiley-VCH Verlag",
number = "6",
}