Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 4: III-V semiconductors: mainly wells and surfaces
HL 4.4: Vortrag
Montag, 11. März 2013, 10:15–10:30, H15
MOVPE-growth and characterisation of GaPN/Si(100) for photoelectrolysis — •Helena Stange1,2, Oliver Supplie1,2, Matthias M. May1,2, Christian Höhn1, Wolf-Dietrich Zabka1,2, Christian Koppka3, Katja Tonisch3, Henning Döscher1,3,4, and Thomas Hannappel1,3,5 — 1Helmholtz-Zentrum Berlin, Institute of Solar Fuels — 2Humboldt-Universität zu Berlin — 3TU Ilmenau, Institut für Physik, Fachgebiet Photovoltaik — 4NREL, Golden, USA — 5CiS Forschungsinstitut für Mikrosensorik und Photovoltaik, Erfurt
Among III-V semiconductors, the dilute nitride GaPN offers a bandgap close to the optimum for the top cell of a
photoelectrochemical tandem device with Si as bottom cell [1,2].
Bandgap engineering permits to adjust the bandgap of GaP to a suitable value by the incorporation of N,
while simultanouesly converting it to a direct semiconductor [3] and achieving lattice match to Si.
We used reflection anisotropy spectroscopy (RAS) and mass spectrometry to monitor GaP and GaPN growth on Si(100) in situ during
metalorganic vapour phase epitaxy.
Via a contamination-free transfer system, we related RAS results with UHV surface science techniques,
such as low-energy electron diffraction and photoelectron spectroscopy.
We applied high-resolution X-ray diffraction and AFM ex situ to analyse the dependence of crystal quality
and surface morphology on MOVPE-parameters such as growth temperature, growth rate, P/N ratio and annealing conditions.
[1] Döscher et al., ChemPhysChem 13 (2012) 2899.
[2] Geisz et al., EUPVSEC 19 (2004).
[3] Wu et al., PRB 65 (2002) 241303.