# RF Wireless World

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## LED Internal Quantum Efficiency and Power output-Definition, equation, calculator

This page describes LED Power output calculation based on LED internal quantum efficiency and other parameters. It mentions LED Quantum Efficiency vs power equation/formula and LED Power output calculator.

Definition:
The fraction of the electrons that are injected into the depletion layer which results in photons getting produced is known as internal quantum efficiency of the LED. It is denoted as η.

If N is the number of electrons injected into the depletion layer every second, the power output of the device is expressed by,
P = η*N*h*v = η*I*h*v/e
Where,
I is forward current
e is the electronic charge
Hence LED Power output equation is derived as follows.

### LED Power Output Calculator based on Internal Quantum Efficiency

LED Radiation ( λ) in nm (input1) :

LED forward current in mA (input2) :

Internal Quantum Efficiency, in % (input3) :

LED Power Output in mW, (Output):

Example:
INPUTS :
LED radiation (λ) = 900 nm,
LED forward current (mA) = 20,
Internal Quantum Efficiency (η) = 2 %
OUTPUTS:
LED Power Output = 0.55 mWatt

### LED Internal Quantum Efficiency Equation | LED Power Output Formula

Following LED internal quantum efficiency vs power output equation or formula is used for this calculator. ### Useful converters and calculators

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