#photocathode  a cathode that emits electrons when illuminated
  supertype:  cathode  a negatively charged electrode that is the source of electrons in an electrical device
  part of:  photoelectric_cell__photoelectriccell__photoconductive_cell__photoconductivecell__photocell__electric_eye__magic_eye__magiceye  a transducer used to detect and measure light and other radiations

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