抄録
Silver which is dispersed as small particles in the intermediate layer of Cs2O photocathode, has the characteristic optical constants of a thin film, and hence has an absorption band in visible range. On the other hand, the spectral sensitivity of the cathode shows a remarkable maximum in visible range. We assume that the selective maximum is due to the volume photoelectric effect corresponding to the foregoing absorption band of silver thin film. We have calculated the light absorption in the surface layer of a silver thin film lying on a glass plate and obtained the spectral sensitivity which is in qualitative agreement with the experimental one.