Light emitting diode (LED) is a junction diode made of gallium arsenide or indium phosphide in which when hole electron pairs recombine at forward biased pn junction, energy is released in the form of light.
Two advantages of LED over conventional incandescent lamps are:
(i) In LED energy is produced in the form of light only, whereas in incandescent lamp energy is produced in the form of heat and light. Thus, there is no energy loss in LED.
(ii) To operate LED, very small voltage (≈ 1V) is required, whereas for the incandescent lamp higher voltages are required.
