The electronic and optoelectronic device technology of III-V semiconductors is based on the growth of complex multilayer structures. The integration of III-V compounds with silicon substrates benefits from the cost-effective and mature Si technology and the outstanding (opto-)electronic properties of III-V semiconductors. A good candidate for heteroepitaxy on Si is GaP, since it is almost lattice-matched to Si. In our team, we utilize angle-resolved X-ray photoelectron spectroscopy (XPS) in combination with gas cluster ion beam (GCIB) etching and synchrotron-based hard X-rays photoelectron spectroscopy (HAXPES) for investigation of atomic and electronic properties of GaP/Si heterostructures and buried heterovalent interfaces. Schematic picture of experimental techniques is shown in figure below. The experimental measurements are supported by an initio DFT calculations and photoelectron intensity simulations.
