# What is photocurrent and stopping potential?

## What is photocurrent and stopping potential?

The photocurrent gradually dies out and eventually stops flowing completely at some value of this reversed voltage. The potential difference at which the photocurrent stops flowing is called the stopping potential.

### What is the effect of potential on photocurrent?

A higher intensity of radiation produces a higher value of photocurrent. For the negative potential difference, as the absolute value of the potential difference increases, the value of the photocurrent decreases and becomes zero at the stopping potential.

#### What is retarding potential difference?

A retarding potential is rejecting photoelectrons from reaching the receiving electrode. So it will be negative on the receiving electrode compared to the photoelectrode. If its extremely negative, it will reject all photoelectrons and circuit current will cease.

What is the difference between photocurrent and photoelectric current?

It may occur as a result of photoemmissive, photovoltaic or photoelectric effect. Photoelectric currenton the other hand is the current that flows as a result of photoelectric effect only. So photoelectric current is photocurrent but not vice versa.

Does photocurrent depend on frequency?

Photoelectronic current depends on the intensity of the light and is independent of the frequency of incident light.

## What is the unit of photocurrent?

Photocurrent Iph is the most important parameter in a photovoltaic cell. It can be calculated using the spectral response, denoted by SR in units of (A/W).

### On what factors do the photocurrent depends?

The photocurrent generated depends on the following factors:

• Frequency of the incident light.
• The intensity of incident radiation:
• The potential difference between the electrodes:
• The photocurrent depends on the photo metal used.

#### How a photocurrent is produced?

The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect. The photocurrent may be enhanced by internal gain caused by interaction among ions and photons under the influence of applied fields, such as occurs in an avalanche photodiode (APD).

What is retarding voltage?

“Retarding” means the retardation of an electron beam in a TEM. In the optical system of the electron microscope, a certain voltage is applied to an additional electrode, a lens or a specimen stage to lower (retard) the velocity of the electron beam.

What is photocurrent response?

Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power. The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect.

## What is photocurrent formula?

Φ = P’ / E = [P/4πr2 × A / hf] If f > f0 (threshold frequency) and photon efficiency of the metal plate is η%, then the number of photoelectrons emitted per second is given by. n = Φη/100 [P/4πr2 × A / hf]] η/100. Finally, the photocurrent i is given by.

### Why is photocurrent independent of frequency?

Originally Answered: Why is photoelectric current independent of frequency? Because frequency doesn’t determine the number of electrons emitted. Magnitude of the photoelectric current is determined by the numbers of electrons emitted per unit area and not energy of the emitted electrons.