Accession Number : AD0644149

Title :   INTERFERENCE PHOTOCATHODES OF INCREASED YIELD WITH FREELY SELECTIVE SPECTRAL MAXIMUM,

Corporate Author : INSTITUTE OF MODERN LANGUAGES INC WASHINGTON D C

Personal Author(s) : Deutscher,K.

Report Date : DEC 1966

Pagination or Media Count : 28

Abstract : The partially permeable metal film of an interference reflector is designed as photoelectrically sensitive film. The reflectivity of the interference photocathode then is zero and/or very low for radiation of a freely selective given wavelength. The greater part of the irradiated luminosity is absorbed in the photofilm. As contrasted with the customary photoelectric monolayer, absorption was increased by a factor of three and electron emision, however, by a factor of nine. This surprising increase of yield is interpreted by the fact that it is possible, in the interference photocathode, to almost completely absorb the luminous energy in the flim lamellae near the surface. By reason of the short range of the photoelectrons in the metal, only the electrons excited in the film lamellae close to the surface have a high probability of emission. The increase of yield over the customary photofilm consequently has as basis that the irradiated luminous energy is absorbed almost completely and the layers have a high effective quantum yield due to the efficient absorption gradient. (Author)

Descriptors :   (*PHOTOCATHODES, INTERFERENCE), METAL FILMS, DIELECTRICS, REFLECTORS, PHOTOELECTRIC MATERIALS, REFLECTIVITY, PHOTOELECTRIC EFFECT, WEST GERMANY

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE