Have you ever understood how led light-emitting diodes work? Let me tell you. Working principle: light-emitting diodes and ordinary diodes are composed of a PN junction, but also has a one-way conductivity. When the light-emitting diode plus forward voltage, from the P region into the N region of the hole and from the N region into the P region of the electron, in the PN junction near a few microns, respectively, with the N region of the electron and P region of the hole complex, generating spontaneous radiation of fluorescence. The energy states of electrons and holes in different semiconductor materials are different. When the electron and hole complexes released when the amount of energy is different, the more energy released, the shorter the wavelength of the light emitted. Commonly used is the diode that emits red, green or yellow light. The reverse breakdown voltage of light-emitting diodes is greater than 5 volts. It has a steep forward voltammetric curve and must be used in series with a current limiting resistor to control the current through the diode.
The core part of a light-emitting diode is a wafer consisting of a P-type semiconductor and an N-type semiconductor, with a transition layer between the P-type semiconductor and the N-type semiconductor called a PN junction. PN junction in some semiconductor materials, the injection of a few carriers and the majority of carriers compound will release excess energy in the form of light, thereby directly converting electrical energy into light energy. pn junction plus reverse voltage, a few carriers difficult to inject, so not light. When it is in the forward operating state (i.e., both ends plus forward voltage), the current flow from the LED anode to the cathode, the semiconductor crystal will emit different colors of light from ultraviolet to infrared, the intensity of light and current-related.