The aim of this internship is to contribute to the study of p-n junction semiconducting NWs regarding their opto-electrical properties. The student will integrate a multi-institute, multi-disciplinary research group. His/her role will be to fabricate electrical contacts to p-n junction NWs of different materials, including GaN and InP. The NWs will be electrically contacted on membrane chips compatible with transmission electron microscopy (TEM) measurements, and the student will be in charge of their electrical and electro-optical characterization. This includes currentvoltage measurements and complete characterization as a   photodetector (responsivity, linearity, spectral selectivity, time response). These results will be correlated to detailed  characterization by transmission electron microscopy, performed on exactly the same single NW. Combining in-situ biasing with the 4D Scanning TEM techniques sensitive to the electric field, we may obtain a quantitative description of the electrical properties of this object at the nm scale. Using this combination of techniques, we will improve our understanding of NW doping, which will aid device fabrication, for instance for NW solar cells.