Our research group specialises in the investigation of different layers using scanning electron microscopy (SEM). This technology enables images to be taken at enormous magnification (up to 1,000,000 times), allowing us to image the layers, some of which are only nanometres thick. With the help of SEM-based methods such as cathodoluminescence (CL), energy dispersive X-ray spectroscopy (EDX) and electron beam induced current (EBIC) measurements, we can investigate the band transitions, elemental composition and current collection in the solar cell with a lateral resolution of less than 10 nanometres. Together with classical analysis methods, this allows us to describe fundamental relationships. The investigation of so-called microcells using high-vacuum mini robots enables us to investigate the relationship between morphological defects and device performance.
Micro solar cells for investigating the influence of inhomogeneities using mini-robots integrated in an electron microscope.
Cross-sections of the layer structure of a CIGS thin-film solar cell: polished cross-section including substrate (right); broken cross-section of the layer structure (top left) Plasma polished cross-section of the layer structure (bottom left).
Images of copper selenide whiskers on CIGS absorbers, taken with a scanning electron microscope.