AVS 60th International Symposium and Exhibition
    Surface Science Wednesday Sessions
       Session SS+EM-WeA

Paper SS+EM-WeA2
Structural Instability in the Adatom Vacancy on Si(111)-√3x√3 Surface: An STM/S Study

Wednesday, October 30, 2013, 2:20 pm, Room 201 A

Session: Semiconductor Surfaces and Interfaces
Presenter: D. Eom, Korea Research Institute of Standards and Science, Republic of Korea
Authors: D. Eom, Korea Research Institute of Standards and Science, Republic of Korea
C.-Y. Moon, Korea Research Institute of Standards and Science, Republic of Korea
J.-Y. Koo, Korea Research Institute of Standards and Science, Republic of Korea
Correspondent: Click to Email
We report a direct probe of the structural instability in the adatom vacancy on heavily boron doped Si(111)-√3x√3 surfaces by using a low-temperature scanning tunneling microscopy/spectroscopy (STM/S). Three dangling bonds (DBs) are generated inside an adatom vacancy on Si(111)-√3x√3 surface, each of which is located at one of three second layer Si atoms with Si(111)-1x1 spacing. The conductance maps of this triple DBs exhibit dissimilar spatial distributions with varying eigenenergies, indicating that the electronic coupling between three DBs is significant due to the proximity. Also, the reduced Cs symmetries of ground and excited states’ wavefunctions of triple DBs, which are probed at -0.25 eV below and +0.3 eV above the Fermi level respectively, contrast to C3v symmetry of underlying 1x1 lattice and are ascribed to Jahn-Teller type instability accompanying degenerate orbital configurations. More detailed analysis of multi-electron configurations and structural instabilities in triple DBs will be reported.