Marco Piccardo has received the PhD award “Innovative Materials and Applications” for his thesis at Ecole Polytechnique entitled “Spectroscopy of photoelectric processes in III-N structures and devices” defended in September 2016. The objective of his work was to identify, by means of direct spectroscopic methods, the mechanisms governing the photoelectric processes and electron dynamics in III-N semiconductors. Two problems in particular were tackled : the excitation and transport of hot electrons, and the role of alloy disorder in optoelectronic devices with InGaN/GaN quantum wells. This work lies in the framework of the great effort made in the field of nitrides, which emerged about 20 years ago with the invention of InGaN/GaN light-emitting diodes, an invention acknowledged by the Nobel prize in Physics in 2014.