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 μm thick freestanding B-10 enriched hexagonal BN (h-¹⁰BN). Two sets of channel peaks corresponding to the neutron capture by ¹⁰B occurring in h-¹⁰BN comprising turbostratic domains (t-¹⁰BN) have been recognized in the nuclear reaction pulsed height spectrum, from which a bandgap of 5.5 eV was directly deduced for t-¹⁰BN. 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. (author)