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I'm very confused, as there are conflicting sources: Why doesn't photoelectric current increase with frequency of the incident wave?

This states that frequency does not affect current because it does not eject more electrons, it only affects the initial kinetic energy of the electrons, which make sense.

However, I'm looking at this simulation here, which when I change the frequency, current is changed: https://phet.colorado.edu/en/simulation/photoelectric

Which one is correct?

Shown by these photos:

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enter image description here

JobHunter69
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  • It is a simulation, it does not reflect reality. Photocurrent is not a simple function of frequency but depends on bulk and surface properties, different for different materials. –  Feb 12 '19 at 00:48

1 Answers1

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I was puzzled by the behavior of the simulation until I read the PhET Tips for Teachers of the Photoelectric Effect (same page as the software on Phet site):

In the default setting, since the intensity of light is proportional to the number of photons times the frequency, if you increase the frequency while holding the intensity constant, the number of photons will decrease. Therefore, if you increase the frequency past the point where all photons are emitting electrons (see previous bullet), the number of emitted electrons (and therefore the current) will start to decrease. Note that this is different from the simplified model used by many textbooks, in which current is constant above the threshold frequency. If you want to be able to change the frequency without changing the number of photons, select “Control photon number instead of intensity” in the Options menu.

GiorgioP-DoomsdayClockIsAt-90
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