DFT investigation of the heterostructure GaP (001) on Si (001)


DFT investigation of the heterostructure GaP (001) on Si (001)

Steinbach, G.; Schreiber, M.; Gemming, S.

Semiconductor multilayers are a versatile tool in optoelectronics. The III-V/IV heterostructure GaP(001) on Si(001) provides a viable and almost lattice-matched stack making it suitable for device applications such as multi-junction solar cells. One of the main challenges still arises from the efficiency limitation due to symmetry breaking and imperfections at the buried GaP on Si interface. Here, we present a density-functional investigation of the interface using both the pseudopotential plane-wave code ABINIT and the all-electron augmented plane-wave code Wien2K. The study distinguishes between the Ga-rich and the P-rich interface termination of GaP in the (001) plane. Overall insight into the interface characteristics is gained from structural and electronic quantities. At the perfectly flat interface, the P-rich variant is found to exhibit higher stability. This is supported by the investigation of the atom distances and the local electronic system. Further, it could be shown that the impact of the interface is very local and does not reach far into the layers. Depending on the interface termination, the electronic system shows distinct behavior.

Keywords: gallium phosphide; silicon; heterostructure; photovoltaic; density-functional; DFT; interface

Permalink: https://www.hzdr.de/publications/Publ-17351
Publ.-Id: 17351