Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 14: Poster I
HL 14.58: Poster
Montag, 24. März 2003, 17:00–19:30, HSZ/P2
Modification of S-GaAs(100) surface properties by deposition of DiMe-PTCDI organic layers — •Henry Mendez1, G. Gavrila1, A. Das1, M. Gorgoi1, F. Winter2, R. Weber2, D. Pop2, T.U. Kampen1, W. Braun3, and D.R.T. Zahn1 — 1Institut für Physik, Technische Universität Chemnitz, D-09107, Chemnitz, Germany — 2U-125/1 beamline (MBI). BESSY GmbH, D-12489 Berlin-Adlershof, Germany — 3BESSY GmbH, D-12489 Berlin-Adlershof, Germany
DiMe-PTCDI was grown on S-GaAs(100). The thickness of the organic film was varied between 0.3nm and 2nm in several steps. After deposition of a thin organic layer photoemission spectra of As3d and Ga3d core levels were taken. The evolution of these core levels as a function of the thickness of the organic film were measured at U-125/1 beamline (Max Born Institute at BESSY II). All the core levels were fitted using previously determined parameters . The results indicate that there is no chemical reaction between the inorganic substrate and the organic layer. The experimental data show a sharpening in the shape of the core levels as a consequence of the deposition of the organic film. The sharpening in both core levels can be taken into account by a reduction of the gaussian contribution in a Voigt profile. This reduction is associated to a diminution of surface inhomogeneities. A Similar observation was already reported for PTCDA, which is similar to DiMe-PTCDI in its molecular structure. Thus, there is experimental evidence showing that both organic molecules stick preferentially on defect sites still present on the S-GaAs(100) substrate. Also, this observation supports the idea of using perylene derivatives like probes for testing defects on surfaces.