TY - JOUR
T1 - Probing carbon impurities in hexagonal boron nitride epilayers
AU - Uddin, M. R.
AU - Li, J.
AU - Lin, J. Y.
AU - Jiang, H. X.
N1 - Funding Information:
The MOCVD growth effort was supported by ARO (W911NF-16-1-0268) and monitored by Dr. Michael Gerhold. The detector fabrication and characterization efforts are supported by the DOE NNSA SSAA program (DE-NA0002927). Jiang and Lin are grateful to the AT&T Foundation for the support of Ed Whitacre and Linda Whitacre endowed chairs.
Publisher Copyright:
© 2017 Author(s).
PY - 2017/5/1
Y1 - 2017/5/1
N2 - Carbon doped hexagonal boron nitride epilayers have been grown by metal organic chemical vapor deposition. Photocurrent excitation spectroscopy has been utilized to probe the energy levels associated with carbon impurities in hexagonal boron nitride (h-BN). The observed transition peaks in photocurrent excitation spectra correspond well to the energy positions of the bandgap, substitutional donors (CB, carbon impurities occupying boron sites), and substitutional acceptors (CN, carbon impurities occupying nitrogen sites). From the observed transition peak positions, the derived energy level of CB donors in h-BN is ED ∼ 0.45 eV, which agrees well with the value deduced from the temperature dependent electrical resistivity. The present study further confirms that the room temperature bandgap of h-BN is about 6.42-6.45 eV, and the CN deep acceptors have an energy level of about 2.2-2.3 eV. The results also infer that carbon doping introduces both shallow donors (CB) and deep acceptors (CN) via self-compensation, and the energy level of carbon donors appears to be too deep to enable carbon as a viable candidate as an n-type dopant in h-BN epilayers.
AB - Carbon doped hexagonal boron nitride epilayers have been grown by metal organic chemical vapor deposition. Photocurrent excitation spectroscopy has been utilized to probe the energy levels associated with carbon impurities in hexagonal boron nitride (h-BN). The observed transition peaks in photocurrent excitation spectra correspond well to the energy positions of the bandgap, substitutional donors (CB, carbon impurities occupying boron sites), and substitutional acceptors (CN, carbon impurities occupying nitrogen sites). From the observed transition peak positions, the derived energy level of CB donors in h-BN is ED ∼ 0.45 eV, which agrees well with the value deduced from the temperature dependent electrical resistivity. The present study further confirms that the room temperature bandgap of h-BN is about 6.42-6.45 eV, and the CN deep acceptors have an energy level of about 2.2-2.3 eV. The results also infer that carbon doping introduces both shallow donors (CB) and deep acceptors (CN) via self-compensation, and the energy level of carbon donors appears to be too deep to enable carbon as a viable candidate as an n-type dopant in h-BN epilayers.
UR - http://www.scopus.com/inward/record.url?scp=85018967427&partnerID=8YFLogxK
U2 - 10.1063/1.4982647
DO - 10.1063/1.4982647
M3 - Article
AN - SCOPUS:85018967427
VL - 110
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 18
M1 - 182107
ER -