8-inch nano-polycrystalline hBN for neutron radiography

Abstract Boron-based scintillators have attracted significant attention due to their high thermal neutron capture cross-section. However, large-area pure boron-based scintillators remain unexplored. Here, an 8-inch pure boron-based thermal neutron scintillator—nano-polycrystalline hexagonal boron nitride (NPhBN) film—was successfully fabricated via high-temperature rapid chemical vapor deposition, achieving full-area uniform and highly efficient luminescence. The NPhBN scintillator exhibits a high photoluminescence quantum yield of 42.5% and an ultrafast neutron response time as low as 14.6 ns, which can be attributed to the carrier confinement effect induced by its nano-polycrystalline structure, thereby enhancing carrier radiative recombination. The neutron radiography systems developed based on this scintillator not only enables large-area multi-object imaging but also clearly reveals the internal structure of metals and organics. Through carrier-confined engineering, this work overcomes the performance limitations of boron-based scintillators, offering a novel technological pathway for large-area multi-object neutron radiography.