Eoin O'Sullivan1,Chelsea Xia1,Dipankar Chugh2,Dillon McGurty1,Nicole Grobert1,Michael Johnston1,Chennupati Jagadish2
University of Oxford1,The Australian National University2
Eoin O'Sullivan1,Chelsea Xia1,Dipankar Chugh2,Dillon McGurty1,Nicole Grobert1,Michael Johnston1,Chennupati Jagadish2
University of Oxford1,The Australian National University2
The optical and electronic properties of hBN – wide band gap, electrically insulating and great thermal transport properties – make it a fascinating 2-D material for electronics and opto-electronics. Introduction of carbon into the lattice has been shown to modulate some of these properties. Recently, carbon doping has been identified as the source of visible quantum emitters in hBN <sup>[1]</sup>. Carbon doped hexagonal boron nitride (hBN-C) has thus been identified as a potential candidate for next-gen semiconductor opto-electronic devices. Previous experimental investigation into hBN-C formation has been limited and lacking comprehensive studies of its structural and electronic properties. Carbon incorporation into hBN can be achieved through various routes depending on the mode of growth. As such, hBN-C films can exhibit differing properties determined by the synthesis method used. Here, carbon doped hBN is synthesized via two methods; Atmospheric Pressure Chemical Vapor Deposition (APCVD)<sup> [2]</sup> and Metal-Organic Vapor Phase Epitaxy (MOVPE)<sup> [3]</sup>, the former a low cost and facile way to produce hBN-C films, the latter a highly sensitive and controlled method of producing 2D hBN-C. Carbon introduction is confirmed via electron energy loss spectroscopy (EELS) and its chemical environment determined via x-ray photo-electron spectroscopy (XPS) results. APCVD hBN-C tends to favour formation of N-C bond, whereas MOVPE samples show a preference of B-C bonding. This variation in bonding results in a distinct contrast in the material properties of hBN-C, as characterized by Raman spectroscopy, UV-vis spectroscopy and Terahertz time domain spectroscopy (THz-TDS). Results presented here suggest that MOVPE hBN-C could be a potential candidate for the engineering of SPEs in the visible range, whereas APCVD hBN-C shows more potential as a material with tunable band gap. This work is relevant to the application of 2D hBN-C in advanced next-gen materials.<br/><br/><sup>[1]</sup> 'Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride', Noah Mendelson, Dipankar Chugh, Jeffrey R. Reimers, Tin S. Cheng, Andreas Gottscholl, Hu Long, Christopher J. Mellor, Alex Zettl, Vladimir Dyakonov, Peter H. Beton, Sergei V. Novikov, Chennupati Jagadish, Hark Hoe Tan, Michael J. Ford, Milos Toth, Carlo Bradac & Igor Aharonovich, Nature Materials, volume 20, pages 321–328 (2021)<br/><sup>[2]</sup> 'Time dependent decomposition of ammonia borane for the controlled production of 2D hexagonal boron nitride', Vitaliy Babenko, George Lane, Antal A. Koos, Adrian T. Murdock, Karwei So, Jude Britton, Seyyed Shayan Meysami, Jonathan Moffat & Nicole Grobert, Scientific Reports volume 7, Article number: 14297 (2017)<br/><sup>[3]</sup> ‘Flow modulation epitaxy of hexagonal boron nitride’, D Chugh, J Wong-Leung, L Li, M Lysevych, H H Tan and C Jagadish, <i>2D Materials,</i> volume 5, article number: 045018 (2018)