Carriers’ recombination and the occurrence of unusually large Auger processes in hexagonal boron nitride

Hexagonal boron nitride (h-BN) is an indirect wide band gap semiconductor that holds great promise for optoelectronic devices over a wide frequency range spanning from UV to mid-IR and serves as a host for quantum light emitters. Here, we report the recombination of photoexcited charge carriers at room temperature in exfoliated monoisotopic ¹⁰B enriched h-BN and investigate the interplay between the bimolecular and Auger processes depending on the excitation fluence. Using ultrafast two-photon excitation transient transmission spectroscopy, we identified three recombination mechanisms described by the ABC model () and measured their associated time scales. The coefficients for the ABC model we found to be (trap-assisted) (bimolecular), and (Auger). We also discuss the unusually large Auger process.