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Understanding the interrelationships between structural and functional properties is key for the Re-design of advanced energy materials. Yet, this requires the investigation of the exact same position of the sample by various microscopy techniques which represent a huge challenge. This challenge has been first faced 10 years ago by Prof. Cojocaru-Mirédin at Max-Planck Institute in Düsseldorf where correlative TEM-APT and EBSD-APT studies (TEM: Transmission electron microscopy, APT: atom probe tomography and EBSD: electron back-scatter diffraction) were for the first time established. This had enabled understanding the interlink between structure (by TEM or EBSD) and composition (by APT) at the grain boundaries of the Cu(In,Ga)Se₂ absorber layer.

Later, the interlink between chemical and structural as well as electrical properties was established for the grain boundaries in multicrystalline Si and polycrystalline Cu(In,Ga)Se₂ absorber layers.

The strategy of the CMC group in the next 5 years is to allow the correlation between composition, structure and transport (such as resistivity, charge carrier density, and mobility) properties for the energy materials of interest. A demonstration of this novel correlative techniques approach is shown below and published recently in Nature Communication.

New EBSD-PPMS-APT correlative techniques platform to be established by the PI. A,B: SEM and 2D EBSD map showing the grain boundary (GB) of interest in a polycrystalline Ag-doped PbTe chalcogenide. C, D: Hall-bar preparation containing the selected GB and mounting of this Hall-bar on a Hall-holder. This configuration is used to measure the resistivity (1/conductivity, E), carrier mobility (F) and carrier concentration not only across the GB, but also of the neighboring grains. G: After the PPMS study, a needle-shaped specimen is prepared by FIB containing the region-of-interest (here the GB) and finally investigated by APT (destructive technique). These illustrations show how APT, SEM/FIB/EBSD, and PPMS can be combined to achieve a truly 1:1 correlative study allowing to understand, which correlations exist between composition, structure, and transport properties.