Dresden 2014 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 68: Heterostructures and interfaces
HL 68.4: Talk
Wednesday, April 2, 2014, 15:45–16:00, POT 051
Heteroepitaxial growth of GaP on Si(111) — •Agnieszka Paszuk1,2, Weihong Zhao1,2, Matthias Steidl1,2, Sebastian Brückner1,2, Anja Dobrich1, Oliver Supplie1, Peter Kleinschmidt1,3, and Thomas Hannappel1,2,3 — 1Technische Universität Ilmenau, Institute for Physics, Ilmenau, Germany — 2Helmholtz-Zentrum Berlin, Institute for Solar Fuels, Berlin, Germany — 3CiS Forschungsinstitut für Mikrosensorik und Photovoltaik, Erfurt, Germany
III-V nanowires exhibit properties for new concepts of high efficiency solar cells. The use of Si instead of III-Vs as substrate benefits from large cost reduction. We prepare thin GaP films on Si as transition buffer layer for subsequent NW growth, since GaP is almost lattice matched to Si. GaP(111) exhibits two polarities, GaP(111)A and B type, which differ by an inversion of the crystal lattice. However, vertical growth of NWs requires GaP(111) layers with B-type polarity. Further, rotational domains might occur in GaP layers during heteroepitaxy, decreasing the crystal quality. Here, we show that surface preparation of Si(111) substrates strongly influences the subsequently grown GaP film polarity during heteroepitaxy by metalorganic vapor phase epitaxy (MOVPE). Low energy electron diffraction (LEED) can be applied to distinguish between the two GaP polarities, which exhibit two different surface reconstructions. X-ray diffraction (XRD) enabled analysis of rotational domains in the GaP buffer layer. Our MOVPE prepared GaP(111)B/Si(111) quasisubstrates enabled vertical growth of III-V NWs.