Photoelectron emission caused by surface plasmons in silver nanoparticles

A new intense band of photoelectron emission peaked at a wavelength of 490 nm has been observed in granular silver films with a nanoparticle size of 10–50 nm. Coinciding with an optical reflection band, the new photoelectron emission peak is related to the excitation of surface plasmons in silver nanoparticles. The quantum yield of photoemission (0.25%) for the new band is approximately equal to that for a longwave band of the classical silver-oxygen-cesium photocathode. It is demonstrated that the photoelectron emission from both photoemitters has a common nature and a time constant on the order of several femtoseconds can be obtained.