PARAMETERS OF THE SPECTRAL-RESOLVED THERMOLUMINESCENCE OF HEXAGONAL BORON NITRIDE

Micropowders of hexagonal Boron Nitride (h-BN) irradiated by ultraviolet light with 210 nm wavelength were studied by the means of thermally stimulated luminescence (TSL) with spectral resolution. Parameters (activation energy, effective frequency factor, kinetics order) were determined for the case of multitrap system. It was shown that TSL in 380 nm and 425 nm was caused by the escape of electrons from single- (1B) and three-boron (3B) centers with energy levels 0.7 and 1.2 eV below the bottom of the conduction band to the Carbon hole levels (C_N-centers) with energy 1.4 eV above the top of the valence band. It was found that under the thermal activation of electron (1B- and 3B-centers) and hole (C_N-centers) traps in the TSL mechanisms the processes of first and second order of kinetics were dominating, respectively. A tunneling mechanism for charge transfer from deep electron traps to 1B- and 3B-centers in heated h-BN samples was proposed.

Keywords:
h-BN, nitrogen vacancy, single-boron center, three-boron center, oxygen and carbon impurity, electron and hole traps, tunneling effect. 
УДК 535.377

PARAMETERS OF THE SPECTRAL-RESOLVED THERMOLUMINESCENCE OF HEXAGONAL BORON NITRIDE