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Cubic boron nitride (cBN) is a relatively less studied wide bandgap semiconductor despite its many promising mechanical, thermal, and electronic properties. We report on the electronic, structural, and optical characterization of commercial cBN crystal platelets. Temperature dependent transport measurements revealed the charge limited diode behavior of the cBN crystals. The equilibrium Fermi level was determined to be 0.47 eV below the conduction band, and the electron conduction was identified as n-type. Unirradiated dark and amber colored cBN crystals displayed broad photoluminescence emission peaks centered around different wavelengths. RC series zero phonon line defect emission peaks were observed at room temperature from the electron beam irradiated and oxygen ion implanted cBN crystals, making this material a promising candidate for high power microwave devices, next generation power electronics, and future quantum sensing applications.
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Atomic-like UV emission generated in hexagonal boron nitride single crystals by thermal annealing
A series of atomic-like photoluminescence (PL) emission peaks in UV region near 4.0 eV were created by thermal annealing hexagonal boron nitride (h-BN) single crystals in air. The pristine h-BN did not have these peaks, emitting strong phonon-assisted band edge PL with peaks at 5.78 and 5.89 eV. After annealing the h-BN crystals in ambient air, a new atomic-like sharp emission in UV region at 4.09 eV with a line width of 0.2 nm appeared along with its phonon replicas at 3.89 and 3.69 eV in the low temperature (8 K) PL measurement. Further testing demonstrated that annealing the h-BN samples in the temperature window of 700–950 °C for 60 min generated the atomic-like emission. The peak position of the emission line is stable with the temperature and PL excitation power. Our study also suggests that the defect responsible for the atomic-like emission resides in the surface region.
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- Award ID(s):
- 2117286
- PAR ID:
- 10549322
- Publisher / Repository:
- Elsevier-ScienceDirect
- Date Published:
- Journal Name:
- Journal of Luminescence
- Volume:
- 275
- Issue:
- C
- ISSN:
- 0022-2313
- Page Range / eLocation ID:
- 120756
- Subject(s) / Keyword(s):
- Hexagonal boron nitride (h-BN) Atomic-like emission Deep UV photoluminescence (PL)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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