2024/04/15 by Sergei Nedić, Karin Yamamura, Nedić, Sergei +7 · 2 citations
Materials Science · #Applied Physics (physics.app-ph) #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Graphene research and applications #Materials Science (cond-mat.mtrl-sci) #Silicon Nanostructures and Photoluminescence
paper · pdf · doi:10.48550/arxiv.2404.09440
openalex publication_date 2024/04/15 · openalex created_date 2024/04/17 · openalex updated_date 2026/08/01
Hexagonal boron nitride (hBN) holds promise as a solid state, van der Waals host of single photon emitters for on-chip quantum photonics. The B-centre defect emitting at 436 nm is particularly compelling as it can be generated by electron beam irradiation. However, the emitter generation mechanism is unknown, the robustness of the method is variable, and it has only been applied successfully to thick flakes of hBN (>> 10 nm). Here, we use in-situ time-resolved cathodoluminescence (CL) spectroscopy to investigate the kinetics of B-centre generation. We show that the generation of B-centres is accompanied by quenching of a carbon-related emission at ~305 nm and that both processes are rate-limited by electromigration of defects in the hBN lattice. We identify problems that limit the efficacy and reproducibility of the emitter generation method, and solve them using a combination of optimized electron beam parameters and hBN pre- and post-processing treatments. We achieve B-centre quantum emitters in hBN flakes as thin as 8 nm, elucidate the mechanisms responsible for electron beam restructuring of quantum emitters in hBN, and gain insights towards identification of the atomic structure of the B-centre quantum emitter.