抄録
The size dependence of the half width of the optical plasma resonance absorption of silver island films has been investigated at 293 K. Below a diameter of about 14 A the deviation from the classical prediction was observed. Considering the average energy level spacing and the level broadening due to scatterings, this deviation was attributed to the quantum size-effect. The level broadening estimated from electron-electron scattering in the optical region was of the order of the average energy level spacing of the particle of about 20 A in diameter. Furthermore, the half width was not changed from 293 to 85 K, which agrees with the prediction based on the temperature dependence of this scattering. Therefore, it was concluded that the conduction band is continuous down to diameters of about 20 A because of the level broadening due to electron-electron scattering.
