F5In-line lamp beads

Like ordinary diodes, light-emitting diodes are composed of a PN junction, and also have single-guide electricity. When a forward voltage is applied to the light-emitting diode, the holes injected from the P region to the N region and the electrons injected from the N region to the P region recombine with the electrons in the N region and the holes in the P region respectively within a few microns near the PN junction to produce spontaneous emission fluorescence. The energy states of electrons and holes in different semiconductor materials are different. When electrons and holes recombine, the amount of energy released is different. The more energy released, the shorter the wavelength of light emitted. Commonly used are diodes that emit red, green or yellow light. The reverse breakdown voltage of the LED is greater than 5 V. Its forward volt-ampere characteristic curve is very steep, and the current-limiting resistor must be connected in series to control the current through the diode.
The core part of LED is a chip composed of P-type semiconductor and N-type semiconductor. There is a transition layer between P-type semiconductor and N-type semiconductor, called PN junction. In the PN junction of some semiconductor materials, when the injected minority carrier and the majority carrier are combined, the excess energy will be released in the form of light, and the electric energy will be directly converted into light energy. PN junction with reverse voltage makes it difficult to inject a few carriers, so it does not emit light. When it is in the forward working state (that is, the positive voltage is applied at both ends), when the current flows from the LED anode to the cathode, the semiconductor crystal will emit different colors of light from ultraviolet to infrared, and the intensity of the light is related to the current.