Supplemental Figures 1-8, Supplemental discussion on the zigzag HB nanoribbon models

Symmetric and asymmetric armchair HB nanorribons, densities of states of different armchair HB nanoribbons, different ordered and disordered zigzag HB nanoribbons, edge energy of ordered and disordered zigzag HB nanoribbons, densities of states of ordered and disordered zigzag HB nanoribbons, correlation between B-H bond length and B-H stretching frequency, IR-active mode in the HB sheet.