Optical absorption and photoemission in semitransparent and opaque Cs3Sb photocathodes

Optical absorption in the visible region is matched to photoelectric emission of cesium - antimonide photocathodes through the use of thin-film equations to explain the greater absorption (and hence greater sensitivity) of opaque-type photocathodes with the same optical constants and thickness of semitransparent ones. The effect is also the same for other popular photocathodes that are used for optical detection.