Optoelectronic properties of hexagonal boron nitride epilayers

X. K. Cao, S. Majety, J. Li, J. Y. Lin, H. X. Jiang

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

4 Scopus citations


This paper summarizes recent progress primarily achieved in authors' laboratory on synthesizing hexagonal boron nitride (hBN) epilayers by metal organic chemical vapor deposition (MCVD) and studies of their structural and optoelectronic properties. The structural and optical properties of hBN epilayers have been characterized by x-ray diffraction (XRD) and photoluminescence (PL) studies and compared to the better understood wurtzite AIN epilayers with a comparable energy bandgap. These MOCVD grown hBN epilayers exhibit highly efficient band-edge PL emission lines centered at around 5.5 eVat room temperature. The band-edge emission of hBN is two orders of magnitude higher than that of high quality AlN epilayers. Polarization-resolved PL spectroscopy revealed that hEN epilayers are predominantly a surface emission material, in which the band-edge emission with electric field perpendicular to the c-axis (Eemi ⊥c) is about 1.7 times stronger than the component along the c-axis (Eemillc). This is in contrast to AIN, in which the bandÂ- edge emission is known to be polarized along the c-axis, (Eemillc). Based on the graphene optical absorption concept, the estimated band-edge absorption coefficient of hBN is about 7x105 cm-1, which is more than 3 times higher than the value for AlN (∼2x105 cm-1. The hBN epilayer based photodetectors exhibit a sharp cut-off wavelength around 230 nm, which coincides with the band-edge PL emission peak and virtually no responses in the long wavelengths. The dielectric strength of hBN epilayers exceeds that of AlN and is greater than 4.5 MV/cm based on the measured result for an hBN epilayer released from the host sapphire substrate.

Original languageEnglish
Title of host publicationQuantum Sensing and Nanophotonic Devices X
StatePublished - 2013
EventQuantum Sensing and Nanophotonic Devices X - San Francisco, CA, United States
Duration: Feb 3 2013Feb 7 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceQuantum Sensing and Nanophotonic Devices X
Country/TerritoryUnited States
CitySan Francisco, CA


  • Hexagonal boron nitride
  • deep UV photonics
  • wide bandgap semiconductors


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