Growth and Characterization of Fe-Ni Flux-Grown Hexagonal Boron Nitride

The growth of high quality Hexagonal Boron Nitride (hBN) crystals is a process that has attracted much interest in recent years. It is a transparent, insulating van der Waals material, and it is commonly used in nanoscale devices as a gate dielectric, tunneling barrier, and as an encapsulating layer for air sensitive devices. Here, we present a novel growth method for hBN synthesized at the MonArk NSF Quantum Foundry facilities at the University of Arkansas. This method uses a Fe-Ni flux at atmospheric pressure, and this talk summarizes our characterization of the resulting crystals.<br/><br/>The bulk crystals yield Raman spectra matching those reported in the literature for other hBN crystal growth methods. Upon exfoliation, we obtain cathodoluminescence spectra for thin flakes, and we compare the energies of the peaks with those reported in the literature. By fabricating parallel-plate capacitor devices, we obtain the dielectric constant and breakdown voltage for a range of thicknesses. We then use hBN synthesized by the Taniguchi and Watanabe group at NIMS to fabricate similar devices and compare the results obtained from both sources. These results establish that hBN crystals grown at the MonArk Quantum Foundry are high quality crystals that have properties comparable to those from other widely used growth facilities.