Abstract
In order to study the enhancement of the ir response of photocathodes, a model describing theeffects of absorption and interference within a semiconductor photocathode supported by a reflectingmetallic substrate is developed. It is shown that the addition of a dielectric spacer between themetallic substrate and the cathode emitter to give a combined optical thickness of quarterwavelength enhances the quantum efficiency of photocathodes over a wider spectral range, and extendstheir maximum response toward the ir. With the choice of dielectric spacer thickness established byan optimum photocathode thickness, a broad spectral response is obtained with reasonably thindielectric and thin photocathode layers. The absorption coefficient very strongly determines thedegree of enhancement which is observed to increase rapidly at the longer wavelengths.
© 1968 Optical Society of America
Full Article | PDF ArticleMore Like This
Tomas Hirschfeld
Appl. Opt. 7(3) 443-449 (1968)
John A. Love and John R. Sizelove
Appl. Opt. 7(8) 1559-1563 (1968)
M. A. Novice and J. Vine
Appl. Opt. 6(7) 1171-1178 (1967)