|It has a light emitting diode.
||It has a light detecting device.
|The LED converts electrical energy into light energy.
||The photodiode converts light energy into electrical energy.
|Due to the recombination of electrons and holes, light is emitted.
||Due to the generation’s electrons holes pairs, the photocurrent will flow.
|LED is works on the principle of Electroluminence.
||Photodiode works on the principle of photoconduction.
|LED changes radiated power due to change in temperature.
||Photodiodes used in fiber optics communications,commerce, flux meter up to coupler etc.
|It uses GaAs, GaAsP or GaP materials.
||It is only uses silicon.