Role of structural defects in the ultraviolet luminescence of multiwall boron nitride nanotubes

BN nanotubes (BNNTs) are structurally similar to their carbon counterparts, though much less investigated. New synthesis methods have been recently reported, enabling the production of industrial quantities and stimulating the search of new applications for the BNNTs. In this paper, we investigate the luminescence of multiwall BNNTs. By performing cathodoluminescence experiments on single tubes at 10 K, we show that the tube luminescence is highly heterogeneous (i) from tube to tube and (ii) spatially along a single tube. By combining cathodoluminescence measurements with a nanometer excitation and transmission electron microscopy on the same tube, we correlate luminescence and structural features. We conclude that the near-band-edge luminescence of BNNTs (approximate to 5.4 eV) is related to the presence of extended structural defects, such as dislocations or ruptures in the wall stacking. (C) 2015 AIP Publishing LLC.