The growth of the III-V semiconductors on a silicon substrate has been studied since the 1980s. Importance of research of this system is increasing during recent years because this material is promising to boost solar energy conversion efficiencies both in photovoltaics and in direct solar water splitting for energy storage. GaP/Si is suitable material for research of the integration of III-V semiconductors with silicon. The XPS and hard X-ray photoelectron spectroscopy (HAXPES) at Spring-8 (Japan) in combination with gas cluster ion beam etching are the methods mainly applied for investigation of GaP-Si interface. Principle of measurement is shown in figure below. The experimental observations are supported by the theoretical calculation of atomic arrangement in the interfaces.
Interface of GaP/Si heterostructure