Explosion-Proof Flashlight Knowledge Of The World Of Luminaries
Writer：Jane Time：2021-07-14 Browse：169 The explosion-proof flashlight light emitting diode is made of Ⅲ- a group of compounds, such as GaAs (gallium arsenide), GAP (gallium phosphide), GaAsp (gallium phosphorus arsenide) and other semiconductors, its core is PN junction. Therefore, it has the general P-N junction I-N characteristics, namely forward wizard through, reverse cutoff, breakdown characteristics. In addition, under certain conditions, it also has luminescent properties. Under the forward voltage, electrons are injected from the n-region into the p-region, and holes are injected from the p-region into the n-region. The minority carriers (minority carriers) entering the other party's region are partly combined with the majority carriers (multi-carriers) and emit light.
Assuming that the emission occurs in the p-region, the injected electrons emit light directly by recombination with the valence band holes, or they are captured by the emission center and then recombination with the holes. In addition to this luminous recombination, some electrons are captured by the non-luminous center (which is located near the middle of the conduction band and the dielectric band), and then recombined with the hole, each time releasing a small amount of energy, which cannot form visible light. The higher the ratio of luminescent recombination quantity to non-luminescent recombination quantity is, the higher the light quantum efficiency is. Because the recombination emits in the minority ion diffusion region, the light is only generated within a few microns of the PN junction.
Theoretically and in practice, it is proved that the peak wavelength of light λ is related to the gap width of semiconductor material Eg in the luminous region, that is, the unit of Eg in the equation λ≈1240/Eg (mm) is electron volt (eV). If visible light can be produced (wavelength between 380nm violet light and 780nm red light), the semiconductor material's EG should be in the range of 3.26 ~ 1.63eV. Light with wavelengths longer than red light is infrared light. Infrared, red, yellow, green and blue light emitting diodes have been available, but the blue light emitting diodes among them cost, price is very high, use is not common.