  We report on spectroscopic study of pyrolytic hBN (pBN) by means of time- and
energy- resolved photoluminescence methods. A high purity of pBN samples
(though low crystallinity) allows complementary information about excited
states involved into the luminescence process. We affirm our recent conclusions
about the impurity-related nature of most of the fluorescence bands in
microcrystalline hBN. In addition, a broad band centred at 3.7 eV previously
not considered because of its superposition with an intense structured impurity
emission is attributed to the radiative recombination of deep DAPs.
