Modification of Shockley surface state by long-chain n-alkane: Photoemission study on tetratetracontane/Au(111) interface

Modification of quasi two-dimensional surface electron system on Au(111) with adsorption of long-chain n-alkane molecule n-CH3(CH2)42CH3 (tetratetracontane: TTC) was investigated by angle-resolved photoemission spectroscopy. Significant modification of the energy band structure of the Shockley surface state was induced by the adsorption of TTC monolayer with “flat-on” structure. The energy shift of the Shockley surface state toward the Fermi level reaches about 160 meV at Γ̄ point (k = 0 Å− 1). The possible origin of the stabilization of the surface electron system with TTC monolayer is discussed.