Momentum resolved electronic band gaps of III-V semiconductor (110) surfaces

Applying in situ combination of angle resolved photoemission and inverse photoemission to cleaved III–V semiconductor (110) surfaces we have investigated the surface gaps between the filled anion derived dangling bond state A5 and the empty cation derived state C3 at the $\bar Γ$, $\bar X$′, $\bar X$, and $\bar M$ point of the surface Brillouin zone. The values of the surface band gaps of each compound increase in this sequence. For $\bar Γ$,$\bar X$′ and $\bar X$ this trend is also found in surface band structure calculations, but, in general, the experimental values are larger than the theoretical ones. The results are compared with optical surface excitations as well as electron energy-loss experiments