Diodes are one of the most common devices in semiconductor devices. Most semiconductors are made of doped semiconductor materials (atoms and other substances). The conductor material of LEDs is usually gallium aluminum arsenide. In pure gallium aluminum arsenide, all atoms are perfectly bonded to their neighbors, leaving no free electrons to connect the current.
In light-emitting diodes, such as those used in digital clocks, the size of the gap determines the frequency of the photons, in other words, the color of the light. While all diodes emit light, most are not very efficient. In ordinary diodes, the semiconductor material itself absorbs a lot of the light energy and ends up. LEDs are covered with a plastic bulb to focus the light in a specific direction.
A form of light that can be released by atoms. It is composed of many tiny particle-like bundles that have energy and momentum but no mass. These particles are called photons, which are the most basic units of light. Photons are released because electrons move around. In atoms, electrons move in orbits around the atom. Electrons in different orbits have different energies. Secara umum, electrons with greater energy move in orbits farther away from the nucleus. When an electron jumps from a lower orbital to a higher orbital, the energy level increases, and conversely, when it falls from a higher orbital function to a lower orbital function, the electron releases energy. The energy is released in the form of photons. Higher energy drops release higher energy photons, which are characterized by their high frequency.
A free electron falls from the P-type layer through the diode into an empty electron hole. This involves falling from the conduction band to a lower orbital function, so the electron releases energy in the form of a photon. This happens in any diode, you just see the photons when the diode is made of a certain material. In a standard silicon diode, Misalnya, the atoms are arranged in such a way that when the electron falls over a relatively short distance, the atoms are arranged in such a way that the human eye cannot see it because the electron frequency is so low.
LEDs have several advantages over traditional incandescent bulbs. The first is that LEDs have no filament to burn out, so they last longer. Selain itu, the small plastic bulb of the LED makes the LED more durable. It can also be more easily fitted into current electronic circuits. The process of emitting light in traditional incandescent bulbs involves generating a lot of heat.
This is a complete waste of energy. Unless you use the light as a heater, most of the effective current does not go directly into visible light. LEDs emit very little heat, so relatively speaking, the more electricity that goes directly into light, the less energy is needed.
For visible light LEDs, such as those used in digital clocks, the size of the gap determines the frequency of the photons, or in other words, the color of the light. While all diodes emit light, most are not very efficient. In ordinary diodes, the semiconductor material itself absorbs much of the light energy and ends up. LEDs are covered by a plastic bulb that focuses the light in a specific direction.
LEDs have several advantages over traditional incandescent bulbs. The first is that LEDs have no filament to burn out, so they last longer. Selain itu, the small plastic bulb of LEDs makes them more durable. They can also be more easily fitted into current electronic circuits. The light-emitting process of traditional incandescent lamps involves the generation of a lot of heat. This is a complete waste of energy. Unless you use the light as a heater, most of the effective current does not go directly into visible light. LEDs emit very little heat, and relatively speaking, the more electricity that is used directly for light, the less energy is needed.
Until now, LEDs have been too expensive for most lighting applications because they are made of advanced semiconductor materials. The price of semiconductor devices has dropped significantly in the past 10 Tahun, however, making LEDs a more cost-effective lighting option for a wider range of applications. In the near future, LEDs will play a larger role in world technology.
A light-emitting diode (LED) is a forward-biased PN junction diode made of semiconductor materials. Its light-emitting mechanism is that when a forward current is injected at both ends of the PN junction, the injected unbalanced carriers (electron-hole pairs) recombine and emit light during the diffusion process. This emission process mainly corresponds to the spontaneous emission process of light. Depending on the location of the light output, LEDs can be divided into surface emission type and edge emission type. The most commonly used LED is the InGaAsP/InP double heterojunction edge light-emitting diode.
The light-emitting principle of LEDs can also be explained by the band structure of the PN junction. The materials used to make semiconductor light-emitting diodes are heavily doped. In the thermal equilibrium state, there are many electrons with high mobility in the N region, and there are more holes with low mobility in the P region. Due to the limitation of the PN junction barrier layer, the two cannot naturally recombine under normal conditions. When a forward voltage is applied to the PN junction, the electrons in the conduction band of the groove region can escape the barrier of the PN junction and enter the P region. Therefore, when the electrons in the high energy state meet the holes in the vicinity of the PN junction slightly to the side of the P region, luminescence recombination occurs. The light emitted by this luminescence recombination belongs to spontaneous radiation, and the wavelength of the radiated light is determined by the bandgap width Eg of the material.
Light-emitting diodes have significant advantages such as high reliability, long continuous working time at room temperature, and good optical power-current linearity. Lebih-lebih lagi, since this technology has been developed to a relatively mature level, its price is very cheap. Therefore, in the design of some simple optical fiber sensors, if LED is competent, choosing it as the light source can greatly reduce the cost of the entire sensor. Namun, the luminescence mechanism of LED determines that it has many shortcomings, such as low output power, large emission angle, spectral line width, and low response speed. Therefore, in the design of some sensors that require high power, fast modulation rate, and good monochromaticity, other higher performance light sources have to be selected at the cost of increasing costs.
Due to the different bandgap widths of different materials, light-emitting diodes made of different materials can emit light of different wavelengths. Selain itu, some materials have different components and doping, Misalnya, some have very complex band structures, and corresponding indirect transition radiation, dll., so there are various light-emitting diodes.