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HL: Fachverband Halbleiterphysik
HL 84: Heterostructures and Interfaces
HL 84.8: Vortrag
Freitag, 24. März 2017, 11:45–12:00, POT 151
Spectroscopic studies of buried GaP/Si(100) heterointerfaces — •Oliver Supplie1, Oleksandr Romanyuk2, Toma Susi3, Matthias M. May1,4, and Thomas Hannappel1 — 1TU Ilmenau, Institute of Physics, D — 2Institute of Physics, Academy of Sciences of the Czech Republic, Prague, CZ — 3Vienna University, Institute of Physics, AU — 4Department of Chemistry, Cambridge University, UK
Pseudomorphic virtual GaP/Si substrates are attractive for III/V-on-Si integration for microelectronics, photovoltaics, and water-splitting applications. Adequate preparation of the GaP/Si(100) heterointerface is of particular interest since its atomic and electronic structure highly impacts crystal quality. Here, we study the formation of the GaP/Si(100) heterointerface in situ during preparation in metalorganic vapor phase epitaxy by means of reflection anisotropy spectroscopy and develop a dedicated nucleation sequence, which yields about 2 nm thin GaP layers on Si(100) with atomically well-ordered surfaces free of antiphase disorder, as evidenced by low energy electron diffraction [1]. Furthermore, we apply photoelectron spectroscopy (PES) on very thin GaP nucleation layers to conclude on the chemical structure of the heterointerface [1]. Density functional theory (DFT) calculations of chemical shifts caused by interfacial bonds support our findings of Si-P bonds being present at the interface [2]. With DFT, we also find interface states in the common band gap above the VBM [2]. Their predicted dispersion is anisotropic and provides distinct features for further experimental PES-based investigation [2]. [1] Supplie et al., JPCL 6, 464 (2015). [2] Romanyuk et al., PRB 94, 155309 (2016).