I saw a diagram of the photosensitivity (Current per Power) of a photodiode.
So there is this diagonal stating the 100% quantum efficiency. I wondered why the sensitivity for bluer light lower than that of redder light.
Is it because a blue photon has a higher energy? Thus fewer blue photons are needed to achieve the same power as with red photons? The photocurrent is proportional to the number of converted photons. So a 1 watt beam in red has more photons, which generate more photo-electrons, thus more current per watt.
Is this reasoning correct and explains the curve in the diagram?