led结构图如下图所示（The LED diagram is shown below）.docVIP

led结构图如下图所示（The LED diagram is shown below） Shenghui advertising color printing (404849558) 23:53:21 The LED diagram is shown below The core part of the LED is a wafer consisting of type P semiconductors and type N semiconductors. There is a transition layer between the P type semiconductor and the N type semiconductor, called the p-n junction. In some PN junctions of semiconductor materials, the injected minority carriers combine with the majority carriers to release excess energy in the form of light, thereby converting the electric energy directly into light energy. PN junction plus reverse voltage, the minority carrier is difficult to inject, so it does not emit light. The diode, produced by injection electroluminescent principle, is called light-emitting diode, commonly known as LED. When it in a positive state of the work (which ends with forward voltage), the current flows from the LED anode cathode, semiconductor crystals on the issue from the ultraviolet to infrared light of different colors light and the strength of the current. Two, LED light source features 1. voltage: LED use low-voltage power supply, the supply voltage is between 6-24V, according to different products, so it is a more secure than the use of high-voltage power supply, especially for public places. 2. performance: incandescent energy consumption is reduced by 80% when. 3. applicability: very small. Each cell LED chip is 3-5mm square, so it can be made into devices of all shapes, and suitable for variable environments 4. stability: 100 thousand hours, 50% for the initial decay 5. response time: the response time of the incandescent lamp is millisecond, and the response time of the LED lamp is nanosecond 6., environmental pollution: no harmful metal mercury 7. color: change the current can change color, led, conveniently through chemical modification method, adjust the energy band structure and band gap, to achieve red, yellow, green, orange, multi-color light emitting. Such as small curre