SMD LED light emitting diode is a commonly used electronic component. Its light emitting principle is mainly realized through the luminescent effect of semiconductor materials.
The structure of the SMD LED light emitting diode is similar to that of an ordinary diode, consisting of two semiconductor materials with different signs (positive and negative voltage directions are opposite). One material is an N-type semiconductor and the other material is a P-type semiconductor. When an electric current passes through, electrons and holes meet near the P-N junction, recombine and release energy. Part of the energy is converted into light energy, thereby emitting light. Therefore, SMD LED light emitting diode is a semiconductor device that can directly convert electrical energy into light energy.
The color of SMD LED light emitting diode is mainly determined by the type and concentration of phosphor contained inside it. Different types of phosphors have different UV wavelength sensitive areas, so when a light-emitting diode emits light, the phosphors can convert part of the UV light into visible light of a specific color.
The light-emitting process of SMD LED light emitting diode can be further explained in detail as the following steps:
Hole injection: When forward current passes through the SMD LED light emitting diode, holes (positive charges) from the P-type semiconductor are injected into the N-type semiconductor, and electrons (negative charges) from the N-type semiconductor are also injected into the P-type semiconductor. A region without main carriers, also called a depletion layer, will be formed near the P-N junction.
Carrier recombination: In the depletion layer, electrons and holes recombine to release energy. In this process, the energy difference between electrons and holes is converted into photon energy, that is, luminescence. The energy of luminescence is related to the band gap of the material, and the luminescence wavelengths of different materials are also different.
Phosphor conversion: In some SMD LED light emitting diodes, phosphor is added inside. These phosphors can absorb part of the ultraviolet light emitted by the light-emitting diode and convert it into other visible light wavelengths. By controlling the type and concentration of phosphors, luminous effects of different colors can be achieved.
Auxiliary structure and light extraction: SMD LED light emitting diode usually also contains some auxiliary structures, such as leads, reflective materials, etc., which are used to assist the extraction and diffusion of light to ensure the effective emission and utilization of light.
These steps together create the luminous effect of the SMD LED light emitting diode. Through material selection, structural design, and the addition of phosphors, luminous effects of different colors and brightness can be achieved to meet various lighting and display needs. SMD LED light emitting diodes are widely used in electronic equipment, lighting, automobiles, communications and other fields due to their high efficiency, reliability and controllability.
In general, SMD LED light emitting diode directly converts electrical energy into light energy through the luminescent effect of the internal semiconductor material, thereby achieving the luminous effect. Its light-emitting principle is simple, efficient and has low power consumption, so it is widely used in lighting, display, signal transmission and other fields.
