Oligomeric aminoborane precursors for the chemical vapour deposition growth of few-layer hexagonal boron nitride†
We explore the use of stable, pre-formed, oligomeric aminoboranes as precursors for the chemical vapour deposition growth of few-layered hexagonal boron nitride (h-BN) films on Cu foils under atmospheric pressure conditions. Dimeric diborazane H3B·NH2BH2·NH3 (DAB), and trimeric triborazane H3B·(NH2BH2)2·NH3 (TAB), derivatives of ammonia borane, H3B·NH3 (AB), are compared with AB, a commonly used precursor for the CVD growth of h-BN. Both DAB and TAB show similar effectiveness to AB in growing h-BN few layered films. Using DAB as the precursor instead of AB leads to fully continuous h-BN films in a shorter period of time. Analysis of the surface of the h-BN films reveals that DAB and TAB precursors deposit more nanoparticles on the surface of the h-BN films during their CVD growth within the same time period as when using AB. The viability of these two new h-BN precursors (DAB and TAB), opens up a wider range of solid-state sources for growing wide band gap h-BN films using CVD techniques.