Influence of the substrate reflectance on the quantum efficiency of thin CsI photocathodes

Performance of thin CsI films operated, at the same time, as reflective and semitransparent photocathodes is presented. Photoemission properties have been analysed on CsI films deposited on aluminium substrates made out of either polished disks or thin films evaporated onto fused silica disks. A comparison between measured values of quantum efficiency (QE) of such photocathodes and the QE of traditional reflective photocathodes is presented.