[en] In this work, we present the experimental study and a theoretical approach of the photoemission of rough and smooth photocathodes. The cathode was made of pure yttrium while its surface was morphologically modified. The cathode surface was irradiated by a KrF excimer at normal incidence. The measurements were performed after electric breakdowns between anode and cathode. For the rough cathode the maximum output current was 10.5 A, with a maximum quantum efficiency value of 1.3 x 10^-4. Instead, the smooth cathode provided an output current of 8.4 A with a maximum quantum efficiency value of 7.0 x 10^-5. In this process, the plasma production and the Schottky effect play a fundamental role