[en] Why a chapter on photoelectronic processes in semiconductors studied by negative electron affinity photoemission, in a volume on hot electrons in semiconductors? It is well-known that standard photoemission uses excitations with energies larger than the work function (≥5 eV) for a clean semi-conductor surface to overcome the surface energy barrier. This corresponds to UV light, so that such an excitation is absorbed in the first few angstroems next to the semiconductor-vacuum interface. Standard photoemission then essentially probes surface properties and is not suited for the analysis of energy relaxation. (author). 115 refs., 38 figs