Session J20: Focus Session: Electronic and Lattice Properties of Surfaces and Thin Films
11:15 AM–2:15 PM, Tuesday, March 11, 2008
Morial Convention Center Room: 212
Sponsoring Unit:
DCMP
Chair: Saw-Wai Hla, Ohio University
Abstract ID: BAPS.2008.MAR.J20.6
Abstract: J20.00006 : Visualization of 2D subband states formed in Si(111)-$\beta -\surd $3x$\surd $3-Bi surface by STM
12:15 PM–12:27 PM
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Abstract 
Authors:
Katsumi Nagaoka
(National Institute for Materials Science)
Shin Yaginuma
(National Institute for Materials Science)
Tadaaki Nagao
(National Institute for Materials Science)
Tomonobu Nakayama
(National Institute for Materials Science)
We have investigated electronic subbands formed underneath of Si(111)-$\beta -\surd $3x$\surd $3-Bi ($\beta -\surd $3-Bi) surface by using STM. The $\beta -\surd $3-Bi surface is semiconducting, and the band gap is larger than that of bulk Si. In the dI/dV images, standing waves are found around defects, and the obtained energy dispersion is in good agreement with the free-electron-like model. Apparently, formation of a 2D electronic state is suggested. However, this standing wave is observed only on p-type, but not on n-type Si substrates, and consequently the 2D state is attributed to the subband formed in the depletion layer just below the $\beta -\surd $3-Bi surface. The subband formation is also consistent with the calculation of electronic states inside a potential-well caused by interfacial band bending.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.MAR.J20.6