Generally, the generation of light energy will be accompanied by the generation of heat, and the bulb will generate heat in the process of light-emitting. The LED bulb in the process of light-emitting is the conversion of electrical energy into light energy. In this conversion process, it is impossible to convert all electrical energy into light energy. According to the law of energy conservation, the remaining part of electrical energy will be converted into heat energy. How much heat is produced? It depends on the luminous efficiency of semiconductor LED. If the luminous efficiency of the LED reaches 40% or 50%, the remaining 60% or 50% of the electric energy will be converted into heat energy in other forms. Under the work of p-n structure, electric energy is transformed into light energy which can be seen by the naked eye through various media. Therefore, the luminous efficiency of LED should consider the input rate of current in LED circuit, luminous efficiency of LED chip, light transfer rate outside the chip and other factors.
With the use of LED bulb, the stability of LED chip will increase, and the temperature rise will further reduce the luminous efficiency, resulting in more heat generation, so that the product has a vicious cycle, resulting in more problems. But how much heat can led bulbs generate?
In the process of LED light-emitting, there is a physical knowledge explanation. In the p-n structure of LED, under the action of electric field, many free electrons obtain electric energy, and jump from the N region to the p region, and compound in the p region. When compound, the free electrons release redundant energy, which is released in the form of photons. The energy difference in the middle will be converted into heat energy.
In the process of electron moving from one n region to another p region, resistance will be encountered, work will be done, part of electric energy will be consumed, and the consumed part of electric energy will eventually be converted into light energy. According to the explanation of physics, the recombination of electron hole pairs in ordinary diodes is due to the factor of energy level difference eg, and the photon spectrum released is not in the range of visible light.
But in fact, when electrons transition from n-zone to P-zone and are compounded in P-zone, they do not directly convert the external electric energy, but the original electronic energy in n-zone is higher than that in P-zone. Only under the action of the external power plant, the electrons in n-zone move to P-zone directionally, and the energy difference of electrons in n-zone and P-zone itself is not provided by the external power plant, which depends on the LED material book Body. So to a certain extent, the basic reason for the generation of LED thermal energy is that the LED luminous efficiency is not high, so that the electric energy can not be efficiently converted into light energy, which will lead to the release of excess energy in the form of thermal energy. So at this stage, we need to fundamentally improve the luminous efficiency of LED, for example, by improving the packaging technology of LED chip, the reasonable use of LED resistance, the efficient use of LED driver, etc., to reduce the generation of heat.