Surface vs. bulk electronic structure of silver determined by photoemission

¹  Department of Physics, University of Illinois at Urbana-Champaign - Urbana, IL 61801-3080, USA
²  Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign Urbana, IL 61801-2902, USA
³  Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1, Sec. 4 - Roosevelt Road, Taipei, Taiwan 10617, Republic of China
⁴  Department of Physics, National Tsing Hua University - 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013, Republic of China

Received: 26 November 2009
Accepted: 27 November 2009

Abstract

Whether photoemission probes surface or bulk properties has long been a topic of interest and debate. This work employs angle-resolved photoemission to map the electronic structure of Ag films of varying thicknesses prepared on Si(111). As expected, the discrete quantum-well states or subbands observed at small thicknesses merge into a continuum as the film thickness approaches the bulk limit. However, a number of discrete states remain isolated within gaps or pockets in the bulk continuum. While these Ag surface states have been predicted previously by calculations, most are experimentally identified herein only for the first time.