Fabrication and ultraviolet photoemission characteristics of novel Au photocathodes

The DC magnetron sputtering was explored to fabricate Au thin films with thicknesses of 5, 10, 15, 20 nm on the silica substrates. These films were annealed in high purity nitrogen ambient at 800℃ and Au particles of different diameters were obtained on the silica substrates. The novel Au photocathodes were prepared by depositing a layer of 50 nm Au film on the silica substrates with Au particles. SEM showed that Au photocathodes with particles ranging from 300-800 nm were obtained. The photoemission characteristics of Au photocathodes under ultraviolet light between 190-360 nm were obtained, which indicated that the novel Au photocathodes with nano-particles emitted 10 times more photoelectrons than the plane Au photocathodes. This result is explained by semi-classical three-step model of photoemission.