Photodiode Quantum Efficiency | Definition, equation, calculator

This page describes Photodiode Quantum Efficiency definition. It mentions Photodiode Quantum Efficiency equation/formula and Photodiode Quantum Efficiency calculator.

What is Photodiode ?

• A photodiode is a type of photodetector capable of converting light into either current or voltage.This effect is called photovoltaic effect.
• DC source is often used to apply reverse bias to the photodiode. This makes it generate more current. This mode of operation is called photoconductive mode.
• Applications of photodiode include optical disc drives, digital cameras and optical switches etc.
• Variants : PIN photodiode, Avalanche photodiode, PN Photodiode, Schottky Photodiode etc.


The figure depicts symbol of Photodiode and one such device from OSRAM. Refer article on Photodiode basics and types and their working operation.

What is Photodiode Quantum Efficiency ?

Definition: The quantum efficiency is defined as fraction of incident photons which are absorbed by photoconductor and generated electrons which are collected at the detector terminal.

In other words, Quantum efficiency is defined as fraction of incident photons which contribuite to photocurrent. It is related to responsivity as per following equation.
Q.E. = 1240 * (Rλ/λ) ;
Rλ = Responsivity in A/W and
λ = Wavelength in nm

Photodiode Quantum Efficiency Calculator

Number of collected electrons/holes, Re (input1) :

Number of incident photons, Rp (input2) :

Quantum Efficiency, η (Output1):

Example of Photodiode Quantum Efficiency calculator:
INPUTS : Re = 1e5, Rp = 1.5e5
OUTPUTS: Quantum Efficiency (Q.E.) = 66.66%

Photodiode Quantum Efficiency Equation | Photodiode Quantum Efficiency Formula

Following equation or formula is used for Photodiode Quantum Efficiency calculator.

Photodiode Quantum Efficiency equation,Photodiode Quantum Efficiency formula

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