Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 26: Poster Session: Heterostructures - Preparation and Characterization - Impurities / Amorphous Semiconductors
HL 26.1: Poster
Montag, 26. März 2012, 16:00–19:00, Poster D
MOVPE growth of lattice-matched GaNP/Si(100) for photoelectrochemistry — •Oliver Supplie1, Matthias M. May1, Henning Döscher1,2, and Thomas Hannappel1,2,3 — 1Helmholtz-Zentrum Berlin, Institut Solare Brennstoffe und Energiespeichermaterialien, D-14109 Berlin — 2TU Ilmenau, Institut für Physik, Fachgebiet Photovoltaik, D-98693 Ilmenau — 3CiS Forschungsinstitut für Mikrosensorik und Photovoltaik, D-99099 Erfurt
III-V dilute nitrides grown lattice matched on Si(100) are considered as a candidate for both hydrogen and oxygen evolution within one single photoelectrochemical tandem device. Heteroepitaxial GaP/Si(100) quasisubstrates combine high quality and inexpensive silicon technology on the one hand (with a band gap close to the optimum for tandem solar cell applications) and a high band gap III-V film with low lattice mismatch to Si on the other hand. Incorporation of N and As in GaP films allows band gap engineering [1] for higher absorbtion and perfect lattice matching to silicon.
We applied reflection anisotropy spectroscopy (RAS) in situ in vapor phase ambient to study both the surface preparation of Si(100), GaP/Si(100) and GaNP/Si(100) as well the growth of the GaNP films. We correlate RA spectra to UHV based surface science techniques accessible via a contamination-free transfer system. For instance, III- and V-rich surface terminations exhibit characteristic RA spectra corresponding to specific surface reconstructions measured with low energy electron diffraction.
[1] Wu et al., PRB 65(2002)241303.; Geisz et al., EPVSEC 19(2004).