Surface properties and work function of ZrB2 single crystal

In this study, the surface convergence, surface energy, and work function on various crystal facets of ZrB2 were investigated by using the density functional theory calculations. Zr-terminated surface exhibits is more stable than the B-terminated surface. The electronic structure calculation reveals that ZrB2 exhibits metallic property, and the high density of states near the Fermi level is mainly composed of Zr-d and B-p orbitals. The work function values of the Zr-terminated (0001), (101¯0), (112¯0), and (112¯1) surfaces of ZrB2 are 4.52, 3.83, 4.00, and 2.56 eV, respectively. We found that the surface energy and work function of ZrB2 (112¯1) are the lowest compared to ZrB2 (0001), (101¯0) and (112¯0) surfaces, exhibiting good surface energy stability and providing excellent electron emission performance. This work provides valuable theoretical guidance for the exploration of ZrB2 as a novel cathode material for electron emission.