The reason and calculation formula of LED lamp fever

Integrated current injection efficiency, luminescent quantum efficiency, chip external light extraction efficiency, and ultimately only about 30-40% of the input electrical energy into light, and the remaining 60-70% of the energy mainly in the non-radiative recombination occurs lattice vibrations in the form of thermal energy conversion.
The chip temperature rises, it will enhance the non-radiative recombination, and further weaken the luminous efficiency. Because the power LED on people's subjective thought no heat, and indeed there is. A lot of heat, so that problems occur during use. In addition, many people first use of high-power LED, the thermal problem they do not know how to effectively solve, making the product reliability has become a major problem. So, led street lighting Manufacturer is there heat generated it? How much heat can produce it? Heat generated by the LED, how much?
The LED forward voltage, electrons gain energy from the power supply, driven by an electric field, the electric field to overcome the PN junction, the transition from N to P zone area, these electrons and holes occur P zone composite. Because the free electrons drift to the P region has an energy higher than the P region of valence electrons, when the recombination of electrons back to the lower energy state, the excess energy is released in the form of photons. The wavelength of the emitted photon energy difference Eg related. Visible light-emitting area is mainly in the vicinity of the PN junction, light is the result of electron and hole recombination due to the release of energy. A semiconductor diode, electrons into the semiconductor region in the semiconductor area to leave all the journey, will encounter resistance. Simply In principle, the physical structure of the semiconductor diode simply from the principle point of view, the physical structure of a semiconductor diode source of electrons emitted from the anode and back to the positive electrode is equal to the number of electrons. Common diode, in the event of an electronic - Compound hole pairs, due to the energy difference Eg factors, photons released not in the visible spectral range.
Electron diode inside the road, are due to the presence of resistance and power consumption. The consumption of power in accordance with the basic laws of electronics:
P = I2R = I2 (RN ++ RP) + IVTH
Where: RN is N zone body resistance
VTH is the threshold voltage of the PN junction
RP is the P zone body resistance
The heat generated by the power consumption is:
Q = Pt
Where: t is time diode energized.
Essentially, LED is still a semiconductor diode. Therefore, LED in the forward work, its work process in line with the above description. It it consumes electric power:
PLED = ULED × ILED
Where: ULED is the forward voltage of the LED light source at both ends:
ILED is the current through the LED
The electric power consumed is converted into heat release:
Q = PLED × t
Where: t for power-on time
In fact, when the energy of the electron and hole recombination zone P release, is not provided directly by the external power source, but because the electrons in the N region when, in the absence of an external electric field, its energy level than the P region valence electron energy level higher than Eg. When it arrives after P area, with the valence electron-hole recombination and become the P region, which will release so much energy. Eg size is determined by the material itself, independent of the external electric field. The role of the external power electronics just pushing it to do directional movement, and to overcome the effects of PN junction.
Nothing to do with the heat production of led street light wholesale effects; not exist a few percent of the electric power to produce light, the relationship between the remaining few percent thermal electric power generation. Produced by high-power LED thermal, thermal resistance, junction temperature of understanding of the concept and the thermal resistance measurement theory and derivation formula, we can study the actual power LED package design, evaluation, and product applications. It should be noted that the thermal management is a key issue luminous efficiency of LED products is not high at this stage, to fundamentally improve the luminous efficiency to reduce the heat generated is drastic move, which requires the chip manufacturing, LED packaging and applications development various aspects of technological progress.