Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Photoelectric efffect question

  1. May 31, 2009 #1
    Hey there,
    I know this may seem like a stupid question but what is the relationship between the maximum electric current and the intensity of light?

  2. jcsd
  3. May 31, 2009 #2
    If you have a thin surface emitting photoelectrons (semitransparent film on the back side of a clear glass window), and a large electric field perpendicular to the surface, like in photomultipliers PMTs), the theoretical maximum quantum efficiency (QE) is 1. In this case, 6.25 x 10^18 photons per sec produces 1 amp of photoelectrons. In actual cases, PMTs have exceeded a QE of 50% at 4000 Angstroms.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook