Some people suggest that the temperature span should be larger than 50 degrees when measure the PN junction temperature by using voltage method. The voltage-temperature relation will be linear in normal working temperature range of LED Lights, it is useless. The room temperature is 25 degree. According to the suggestion mentioned above, next measuring temperature be around 75 degree. However, the upper limit of the normal working temperature of LED PN junction is 70 degree. Is there any reason f...Continue reading

More and more people realize that estimating the specific temperature of LED chips by measuring LED lamps covers temperature is inaccurate. However, how to get the exact temperature of LED PN junction? At present, there are three commonly used PN junction temperature measuring methods: thermal resistance method, voltage method and thermal imagine method.     Thermal imagine method requires very expensive instruments which cannot be afforded by ordinary people. However, usi...Continue reading

As we all know, light color of LED can be determined by materials used in n-type region and p-type region, and light intensity is determined by the number of carriers within LED Street Light. Carriers’ number is not fixed in diodes. Temperature can exert a significant influence on it. With the increase of temperature, the intrinsic excitation effect will be enhanced. More electron-hole pairs will be generated in n-type region and p-type region respectively. This additional electron-hole pairs wi...Continue reading

3.  Electrons in the edge of p-type section. Electrons pass LED PN junction and finally reach the edge of p-type section. Most of them will be captured by the large amount of holes within p-type section. Since electrons have higher potential energy than holes, after being captured by holes, this potential energy will be released as the form of electromagnetic wave (LED Street Light). The light color all depends on the material of diodes. Different diodes has different band gap (different potenti...Continue reading

LED (light-emitting diode) is a kind of one-way conductive electronic component. Generally, diode is a PN junction composed by a p-type semiconductor and an n-type semiconductor. An equilibrium condition is reached within the space charge region in the condition of zero bias.     At room temperature, why do carriers within LED PN junction generate heat along with light? Electrons in n-type section. Under positive bias (the normal operating condition for LED Street Ligh...Continue reading