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

- All Efficiency Calculators
- Photon Energy Calculator
- Diffraction Efficiency Calculator
- Spectral Efficiency Calculator

## 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:**

- First, determine the number of electrons collected. In this example, the number of electrons collected is given as 250.
- Next, determine the number of incident photons. For this problem, the number of incident photons is given as 321.
- 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