Band-structure engineering of gold atomic wires on silicon by controlled doping.
We report on the systematic tuning of the electronic band structure of atomic wires by controlling the density of impurity atoms. The atomic wires are self-assembled on Si(111) by substitutional gold adsorbates and extra silicon atoms are deposited as the impurity dopants. The one-dimensional electronic band of gold atomic wires, measured by angle-resolved photoemission, changes from a fully metallic to semiconducting one with its band gap increasing above 0.3 eV along with an energy shift as a linear function of the Si dopant density. The gap opening mechanism is suggested to be related to the ordering of the impurities.
Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
Won Hoon
WH
Choi
Pil Gyu
PG
Kang
Kyung Deuk
KD
Ryang
Han Woong
HW
Yeom