title: Physical origin of hydrogen-adsorption-induced metallization of the SiC surface: n-type doping via formation of hydrogen bridge bond.
abstract: We perform first-principles calculations to explore the physical origin of hydrogen-induced semiconductor surface metallization observed in beta-SiC(001)-3 x 2 surface. We show that the surface metallization arises from a novel mechanism of n-type doping of surface band via formation of hydrogen bridge bonds (i.e., Si-H-Si complex). The hydrogen strengthens the weak Si-Si dimers in the subsurface by forming hydrogen bridge bonds, and donates electron to the surface conduction band.
authors.affiliation: Department of Physics and Center for Advanced Study, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chang
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Bing-Lin
authors.initials: BL
authors.lastname: Gu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Wenhui
authors.initials: W
authors.lastname: Duan