The adsorption of Be on the surface of (0 0 0 1) InN

To understand n-type InN doping with Be, first-principle calculations are performed to obtain the various kinds of surface-structure for Be adsorbed on InN(0 0 0 1) surface. An InN(0 0 0 1)-(2 × 2) surface structure with 0.25 monolayer-coverage of Be absorbing at the T4 sites is most energetically favorable. Meanwhile, nitrogen (N) vacancy can form spontaneously. Be atoms may also substitute N atoms or simply stay on the surface during growth, which may induce surplus n-type carriers.