# Does photocurrent depend on intensity or on number of photons?

Edit: I have realised my mistake. The part of text I read assumed the light to be monochromatic and so in that case, there will be no difference between intensity and number of photons because the frequency remains same. Thanks to @planetmaker

Anyway here's the original question:

Any textbook I have read so far says that the amount of saturation current depends on intensity but not frequency.

How can the two (viz. intensity and frequency) be unrelated when intensity is quite literally defined as energy falling per unit area in a unit time and energy $$E$$ is simply proportional to frequency $$\nu$$ as

$$E=h{\nu}$$

So the intensity of a light source producing $$n$$ photons per unit time and each photon having energy $$E$$ is given as

$$I=\frac{nh\nu}{A\cdot t}$$ ($$A$$ and $$t$$ represent area and time respectively)

So in a scenario where I keep the number of photons $$n$$ constant but change the frequency $$\nu$$, will the saturation photocurrent change? If it does not change, does that mean the statement, “Saturation photocurrent depends only on intensity and not frequency” is invalid and it should rather be, “Saturation photocurrent depends only on number of photons incident per unit time and not frequency”?

PS: I have read answers to similar questions but I didn’t get a clear clarity from any of those.

• What is the difference (for monochromatic light) between 'intensity' and 'number of photons? Commented Jul 13 at 16:09
• Where did you read that "Saturation photocurrent depends only on intensity and not frequency"? Commented Jul 13 at 16:18
• @planetmaker I get it now. I was wrong Commented Jul 13 at 16:27