Enter the number of electrons collected and the number of incident photons into the calculator to determine the Quantum Efficiency. 

Quantum Efficiency Formula

The following formula is used to calculate the Quantum Efficiency. 

Eq = EC / IP

  • Where Eq is the Quantum Efficiency
  • EC is the number of electrons collected 
  • IP is the number of incident photons 

How to Calculate Quantum Efficiency?

The following two example problems outline how to calculate the Quantum Efficiency.

Example Problem #1:

  1. First, determine the number of electrons collected. In this example, the number of electrons collected is given as 250.
  2. Next, determine the number of incident photons. For this problem, the number of incident photons is given as 321.
  3. Finally, calculate the Quantum Efficiency using the equation above: 

Eq = EC / IP

Inserting the values from above and solving the equation: 

Eq = 250 / 321 = .778


Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are:

number of electrons collected = 231

number of incident photons = 984

Entering these values yields:

Eq = 231 / 944 = .244