LIX.The photoelectric properties of thin films of the alkali metals

Abstract

The thin films mainly studied are those produced by depositing an alkali metal on some other material, driving it off by heat, and subjecting the remaining film to a discharge in hydrogen. By this process photoelectric cathodes can be pro luced that have very remarkable and stable sensitivity to-red light; photoelectric currents can be obtained with light of λ 8000 A of the same order as those obtained in normal potassium cells with light of λ 4500 A. The sensitivity depends very greatly on the material on which the film is deposited.