Low temperature CL investigation of BN1 vibronic structure in c-BN

• Published in: Diamond and related materials Vol. 15; no. 4; pp. 1166 - 1168
• Main Authors: Cossio, R., Fizzotti, F., Vittone, E., Lo Giudice, A., Manfredotti, C., Nistor, S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2006; Elsevier
• Subjects: c-BN; Cathodoluminescence; Condensed matter: structure, mechanical and thermal properties; Defect centres; Exact sciences and technology; Physical radiation effects, radiation damage; Physics; Structure of solids and liquids; crystallography; Vibronic structure; Defect centres; c-BN; Cathodoluminescence; Vibronic structure; Radiation effects; Cubic lattices; Vibronic states; Boron nitrides; Interstitials; Electron beam; Vibronic analysis; High pressure
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2005.11.048

A full vibronic spectrum has been measured for the first time by LNT Cathodoluminescence in HPHT c-BN amber-coloured microcrystalline samples. The related BN1 centre at 3.293 eV seems not created by electron irradiation in this case and the accurately determined phonon energy (141
±
3 meV) could be related to LO phonon at
X point in Brillouin Zone (BZ) of c-BN, as determined by CL results obtained at indirect gap. Consequently, BN1 centre has not the full cubic symmetry of c-BN, as being due to N interstitials. The interpretation of the results is possibly two-fold: either we are observing a vibronic spectrum with ZPL at BN1 centre, together with other two centres called PF-1 and PF-2 at 3.573 and at 3.412 eV, respectively, or, since all the 6 or 7 observed peaks are exactly equally spaced, the whole vibronic spectrum is related to a ZPL line at 3.573 eV. This new interpretation seems to be in better agreement with the general theory of colour centres.