Origin of the surface metallization in single-domain K/Si„100...231


The electronic structure and the metallization onset of single-domain K/Si~100!231 have been investigated with angle-resolved polarization-sensitive ultraviolet photoemission. The electronic states producing the surface metallization have been studied for increasing K coverages up to room-temperature saturation. As K coverage increases, the interface undergoes a transition at a critical coverage, from a low-coverage semiconducting phase, to a saturation-coverage metallic phase. Two different surface states (F1 and F2) have been detected in the vicinity of the Fermi level. These two states are sequentially filled along the metallization process. The coverage dependence of both F1 and F2, and their symmetry properties indicate that the metallization is due to the filling of an initially empty surface band ~appearance of F2). We relate F1 to the completion of K chains in the single-domain surface. The changes detected in K 3p line shape correlate well with the modifications of the valence band, and support that the surface remains semiconducting up to the filling of F2. @S0163-1829~96!51844-8#

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@inproceedings{Segovia1996OriginOT, title={Origin of the surface metallization in single-domain K/Si„100...231}, author={Pilar Segovia and German R Castro and Arantzazu Mascaraque and P. Prieto and Heon Jung Kim and E G Michel}, year={1996} }