Anisotropic electronic band structure of intrinsic Si(110) studied by angle-resolved photoemission spectroscopy and first-principles calculations

We have studied the electronic band structure of the hydrogen-terminated Si(110)-($1\ifmmode\times\else\texttimes\fi{}1$) [H:Si(110)-($1\ifmmode\times\else\texttimes\fi{}1$)] surface using angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations in the framework of density functional theory with local density approximation (LDA). The bulk-truncated H:Si(110)-($1\ifmmode\times\else\texttimes\fi{}1$) surface is a good template to investigate the electronic band structure of the intrinsic Si(110). In the ARPES spectra, seven bulk states and one surface state due to the H-H interaction are observed clearly. The four bulk states consisting of Si $3{p}_xy$ orbitals exhibit anisotropic band dispersions along the high symmetric direction of $\overline{\mathrm{\ensuremath{\Gamma}}}\ensuremath{-}\overline{\mathrm{X}}$ and $\overline{\mathrm{\ensuremath{\Gamma}}}\ensuremath{-}{\overline{\mathrm{X}}}^{\ensuremath{'}}$ directions, where one state shows one-dimensional character. The calculated band structures show a good agreement with the experimental results except the surface state. We discuss the exact nature of electronic band structures and the applicability of LDA. We have estimated the anisotropic effective masses of electrons and holes of Si(110) for device application.