Probing the bandgap and effects of t-BN domains in h-BN neutron detectors

Thermal neutron detectors in a lateral scheme were fabricated from a 70 mu m thick freestanding B-10 enriched hexagonal BN (h-(BN)-B-10). Two sets of channel peaks corresponding to the neutron capture by B-10 occurring in h-(BN)-B-10 comprising turbostratic domains (t-(BN)-B-10) have been recognized in the nuclear reaction pulsed height spectrum, from which a bandgap of 5.5 eV was directly deduced for t-(BN)-B-10. Improved device performance over the prior state-of-the-art implies that the transport properties in the lateral plane of t-BN domains are sufficiently good and their presence in h-BN is not a showstopper for the further advancement of h-BN detector technologies.