Photoluminescence properties of pyrolytic boron nitride

TL;DR

This study investigates the photoluminescence characteristics of pyrolytic boron nitride using advanced spectroscopic techniques, revealing impurity-related emissions and identifying a new broad emission band at 3.7 eV linked to deep defect-related recombination.

Contribution

It provides new insights into the excited states and impurity-related luminescence mechanisms in pyrolytic boron nitride, including the identification of a previously overlooked emission band.

Findings

Impurity-related nature of most fluorescence bands in microcrystalline hBN

Identification of a broad emission band at 3.7 eV

Attribution of this band to deep defect-related recombination

Abstract

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.