| LED | photodiode |
|---|---|
| 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. |