Formation of heterorelevant interfaces: A combined photoemission and ab initio DFT study of GaP/Si heterostructures

Contact person

Prof. Thomas Hannappel
Group for Fundamentals of Energy Materials

Phone: +49 3677 69-2566


Funding information

Project leader: Deutsche Forschungsgemeinschaft

Project number: HA 3096/10-1

Participating group: Group for Fundamentals of Energy Materials

Period of funding:01.07.2018 - 30.06.2021

Project information

Integration of III-V semiconductors on Si is desirable for new generation of microelectronic power devices, high-efficiency multi-junction solar cells and photolytic tandem absorbers for the renewable generation of hydrogen. GaP/Si(001) is the ideal candidate for generic, pseudomorphic virtual substrates aiming to overcome complex issues related to polar-onnonpolar heteroepitaxy prior further III-V integration. Preparation of sharp GaP/Si(001) interfaces thereby is the critical technological step in metalorganic chemical vapor deposition (MOCVD) because it strongly impacts the quality of subsequently grown epitaxial films and the final device performance. Preliminary work showed that Arsenic is of particular interest here.

Today, interface formation mechanisms are not well understood at the atomic scale and the electronic structure of buried interfaces is not resolved. In this bilateral project, we will combine optical insitu spectroscopy, lab-based as well as synchrotron-based photoelectron spectroscopy techniques, depth profiling and ab initiodensity functionaltheory (DFT) calculations in order to establish a comprehensive atomic-scale understanding of the structural and electronic properties of GaP/Si(001) and GaP/Si(001):As heterointerfaces. We will introduce dedicated modifications of the atomic structure in order to understand how the electronic properties of the heterointerface can be tuned. The objective is to gain a fundamental understanding of III-V/IV heterointerface formation with direct implications for high-efficiency device applications.