Why the LED light especially the high power LED lights including the high power LED flood light generating the heat is because that all of the electricity inputted is not turn into light energy , but considerably majority of which is transformed into heat. LED light efficiency is currently only 100lm / W, the electro-optical conversion efficiency is only about 20 to 30%. That is about 70% of the electrical energy wasted into heat .
Specifically , the junction temperature of especially the high power LED flood light and other power LED light is generated due to two factors .
1 . Internal quantum efficiency is not high , that is, when the electron recombines the hole, which can not produce 100% of all photons, commonly referred to as the ” current leakage ” of carriers leaving the PN zone composite rate. Leakage current times the voltage is the power of this part, which is converted into heat , but this part does not account for the main component , because the internal photon efficiency is close to 90%.
2 . photons Internally generated can not be fully emitted to the outside of the chip and finally converted to the heat, which is the main part , referred to that the external quantum efficiency is currently only about 30% , most of which is converted into the heat .
Although the light efficiency of incandescent is very low , only 15lm / W or so, the considerably majority of the electrical energy light energy is converted into heat , which is that same as the high power LED flood light and other LED lights or other lamps，the rest electricity is converted into light radiated since most of the radiation is infrared therefore very low efficiency, but eliminating the problem of heat dissipation .Browsing http://www.lead-lighting.com/products/sid125-1.htm for more information about the high power LED flood light.