Why Doesn't Photoelectric Current Immediately Maximize Above Stopping Potential?

[neelakash]

Homework Statement

Why does the photoelectric current I not rise vertically up to its maximum value when the applied potential difference is slightly more positive that the stopping potential?

Homework Equations

The Attempt at a Solution

Simply because,the speed of the photoelectrons also depend on the potential difference they are passing through[apart from the incident ray intensity].As they move their KE becomes converted into PE.As you vary the voltage,the current should vary accordingly...

I do not find any more good reasoning behand this...Can anyone please check?

 

[Jhero]

Thank you for your question. The reason for the photoelectric current not rising vertically up to its maximum value when the applied potential difference is slightly more positive than the stopping potential is due to the relationship between the stopping potential and the work function of the material. The stopping potential is the minimum potential required to stop the flow of photoelectrons, and it is directly related to the work function of the material. The work function is the minimum energy required to remove an electron from the surface of the material.

When the applied potential difference is slightly more positive than the stopping potential, the photoelectrons are still able to overcome the work function and be emitted from the material. However, the additional potential difference does not significantly increase the energy of the photoelectrons. This is because the photoelectrons already have a high energy from the incident light. As they travel through the potential difference, they experience a decrease in energy due to collisions with other particles in the material. This decrease in energy counteracts the increase in energy from the additional potential difference. As a result, the photoelectrons do not gain a significant amount of energy and the photoelectric current does not rise vertically to its maximum value.

I hope this explanation helps to clarify the concept. Please let me know if you have any further questions. Thank you for your interest in the photoelectric effect.