Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 18: Semiconductor Substrates: Structure, Epitaxy and Growth
O 18.3: Vortrag
Montag, 20. März 2017, 16:30–16:45, WIL C307
Surface Structure of MOVPE-prepared GaP(111)B — •Peter Kleinschmidt1, Pingo Mutombo2, Oleksandr Romanyuk2, Marcel Himmerlich3, Theresa Berthold3, Xin Wen1, Andreas Nägelein1, Matthias Steidl1, Agnieszka Paszuk1, Oliver Supplie1, Stefan Krischok3, and Thomas Hannappel1 — 1Photovoltaics Group, Institute of Physics, Technische Universität Ilmenau, 98684 Ilmenau, Germany — 2Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 00 Prague 6, Czech Republic — 3Technical Physics I, Institute of Physics and IMN MacroNano, Technische Universität Ilmenau, 98684 Ilmenau, Germany
We have characterized the structure of MOVPE-prepared GaP(111)B surfaces by STM, XPS and ab intio DFT. After deoxidation under tertiarybutylphosphine and subsequent annealing in H2, STM images show flat terraces with an atomic surface structure which is congruent with the underlying lattice, but only locally exhibits ordered regions of (2 × 2), c(4 × 2) and (√3 × √3) reconstruction. We identify the protrusions in the images as dangling bonds of an otherwise H-terminated phosphorus face. The DFT calculations predict a (2 × 2)-3H and c(4 × 2)-3H reconstruction under H-rich conditions, while the (√3 × √3)-2H reconstruction is less favorable. Preparation without annealing in H leads to a P-rich surface with an additional adlayer of trimers.