Macroscopic sheets of hydrogen boride and their spectroscopic evaluation

Macroscopic sheets of hydrogen boride (HB) were fabricated by annealing microflakes, synthesized after the ion-exchange reaction. The sheets were centimeters wide and a micrometer thick. Handy and easy handling of the sheets has allowed us to conduct spectroscopic evaluations over various photon energy ranges. X-ray absorption spectra at the B K-shell absorption edge were obtained; the narrow spectral peaks were reproduced in theoretical simulations, revealing bonding characters between the H and B atoms. The macroscopic fabrication demonstrated in the present research offers a bottom-up approach toward real-world applications of these HB sheets.