Pass Cylindrical Mirror Analyzer Research Articles

Surface photoelectric effect and surface orbital geometry on silicon (111)

Photoelectron energy distributions have been measured as a function of photon angle of incidence, ϑi, in the range 28°?ϑi?80°. A resonance lamp with photon energies of 11.7, 16.8, and 21.2 eV was used with a double−pass cylindrical mirror analyzer. Three different surface orbitals were studied: intrinsic surface states, chemisorption orbitals of Cl, and nonbonding orbitals of implanted Ar. All three types of orbitals exhibited a similar dependence of intensity with ϑi which was approximately the same as the net electric field intensity 〈E2z〉z = 0. This implies that the surface photoeffect for silicon (111) is probably not closely related to the detailed surface bond geometry, but is determined by the optical properties of the silicon.