We investigate different scientific questions - sometimes using specialized analytical methods - that arise during fabrication and characterization of heterostructures:
The fabrication of heterostructures usually starts by preparing a suitable semiconductor surface. An important step to this end is the wet-chemical conditioning of silicon substrates.
Afterwards, silicon heterostructures are created by deposition of very thin semiconductor films on the substrate surface, e.g. using PECVD. An important aspect of our work is the characterization of defect states in these ultra-thin films.
The finished heterojunctions can be characterized with different methods such as surface photovoltage (SPV), photoelectron spectroscopy (XPS, UPS, near-UV PES). Thus, band bedings, defect densities, band offsets and other heterojunction parameters can be determined.