Effect of Intensity and Frequency on Photoelectric Current

[bittu222]

what will be the effect on photoelectric current if the intensity and frequency of incident photons are increased simultaneously. ? Will the current remain almost same? if so , why?

 

[Bob S]

The photoelectric current (like in a vacuum photodiode) increases linearly with the intensity (for a particular color light).
The photoelectric current is zero above a particular wavelength threshold (below a particular frequency threshold). Above the frequency threshold, the current increases slowly as the frequency is increased, depending on the characteristics of the photocathode.
The photocurrent will increase if BOTH intensity and frequency are increased simultaneously, again depending on the characteristics of the photocathode. See spectral response characteristics on page 4 of
http://sales.hamamatsu.com/assets/pdf/parts_R/LARGE_AREA_PMT_TPMH1286E05.pdf
Bob S

 

[Entropia]

The photoelectric effect is a phenomenon in which electrons are emitted from a metal surface when it is exposed to light of a certain frequency. The intensity and frequency of the incident photons are two key factors that affect the photoelectric current.

If both the intensity and frequency of the incident photons are increased simultaneously, the photoelectric current will also increase. This is because the number of photons hitting the metal surface will increase with the increase in intensity, and the energy of each photon will increase with the increase in frequency. As a result, more electrons will be emitted from the metal surface, leading to an increase in the photoelectric current.

However, it is important to note that there is a limit to the increase in photoelectric current with the increase in intensity and frequency. This is because at high intensities and frequencies, the electrons may not have enough time to escape the metal surface before being hit by the next photon. This can lead to a saturation of the photoelectric current, where further increases in intensity and frequency will not result in a significant increase in current.

In addition, the work function of the metal also plays a role in determining the photoelectric current. The work function is the minimum amount of energy required to remove an electron from the metal surface. If the energy of the incident photons is lower than the work function, no electrons will be emitted, regardless of the intensity and frequency.

In summary, the photoelectric current will increase with an increase in intensity and frequency of incident photons, but there is a limit to this increase due to factors such as saturation and the work function of the metal. Therefore, the current will not remain the same, but it will reach a maximum value at high intensities and frequencies.