Work Functions of Boron Nitride Nanoribbons: First-Principles Study

Using first-principles method, we study the work functions and effective work functions of boron nitride nanoribbons (BNNRs) with and without hydrogen decoration. Zigzag BNNRs (ZBNNRs) are typical non-symmetric systems and their work functions and effective work functions are difficult to be determined based on the supercell method due to the gradient potential distribution in the vacuum region. Dipole and potential correction (DPC) are adopted in our present work. By using DPC, we first show that when the tips of SWBNNT(8, 0) (also typical non-symmetric system) are terminated by hydrogen, the work function decreases at the N tip but increases at the B tip. The work functions and effective work functions of the BNNRs with different hydrogen decoration are calculated using the same mehod. We find that the N edge of the full-hydrogen adsorbed ZBNNR (FH-ZBNNR) is a promising field emission candidate due to its low work functions and effective work functions.