Premium
The Geometric Structure of Silver‐Doped Silicon Clusters
Author(s) -
Li Yejun,
Lyon Jonathan T.,
Woodham Alex P.,
Fielicke André,
Janssens Ewald
Publication year - 2014
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201300944
Subject(s) - dopant , silicon , crystallography , atom (system on chip) , doping , materials science , density functional theory , chemistry , computational chemistry , optoelectronics , computer science , metallurgy , embedded system
Cationic silver‐doped silicon clusters, Si n Ag + ( n =6–15), are studied using infrared multiple photon dissociation in combination with density functional theory computations. Candidate structures are identified using a basin‐hopping global optimizations method. Based on the comparison of experimental and calculated IR spectra for the identified low‐energy isomers, structures are assigned. It is found that all investigated clusters have exohedral structures, that is, the Ag atom is located at the surface. This is a surprising result because many transition‐metal dopant atoms have been shown to induce the formation of endohedral silicon clusters. The silicon framework of Si n Ag + ( n =7–9) has a pentagonal bipyramidal building block, whereas the larger Si n Ag + ( n =10–12, 14, 15) clusters have trigonal prism‐based structures. On comparing the structures of Si n Ag + with those of Si n Cu + (for n =6–11) it is found that both Cu and Ag adsorb on a surface site of bare Si n + clusters. However, the Ag dopant atom takes a lower coordinated site and is more weakly bound to the Si n + framework than the Cu dopant atom.