LEDs are solid state semiconductor devices that convert electricity directly into light. Thermal sources of light such as flames and incandescent filaments emit light when heated, or chemical reaction (flames) or electrical heating (filament lamps). LED “cold” generation of light leads to high efficiency, because most energy radiation in the visible spectrum. Other common high efficiency sources of light such as fluorescent lamps and electric appliances gleaming, also produce light without much thermal radiation outside the visible spectrum. Since SSD LED devices, they can be very small and stable, they also provide longer lamp life than other sources. Light is produced within the chip, a solid crystalline material, when a current flows through the nodes of various material makeup. LED consists of two elements of processed material called P-type semiconductors and N-type semiconductors. These two elements are in direct contact, forming a region called the PN junction. The composition of different materials and so set the wavelength of light colors. LED seems most other species, but there are important differences. LED has a transparent package, allowing energy to pass through the visible or IR. Also, LED is a large-area PN union whose shape is adapted for application. The device is shown in Figure 1 is AlGaInP LED because the semiconductor layer of aluminum (Al), gallium (Ga), indium (In) and phosphate (P). Main MaterialsThe LED main semiconductor materials used to manufacture LEDs are: * indium gallium nitride (Inga), blue, green and ultraviolet high-brightness LEDs indium gallium aluminum phosphide * (AlGaInP): yellow, orange and red high-brightness LEDs * aluminum gallium arsenide (AlGaAs) red LEDs and infrared gallium phosphide * (GAP): yellow and green LED Why LED? LEDs have several advantages that are quickly they the best choice for lighting really energy efficient. Over the next few years, some aspects are expected to change significantly. LifetimeAs semiconductor light sources, LEDs have a very long life and are generally more robust due to any mechanical or moving parts. incandescent bulbs have a lifespan 1k to 5k hours, while a good quality LED is often quoted that the life of 50K hours, more than five years of continuous use. But it is important to understand that the performance of LEDs degrades over time, and this degradation is affected by many factors such as current and operating temperature. low life long maintenanceThe LEDs reduces the need for lamp replacement failed, and this can lead to significant financial savings and environmental issues, particularly in the maintenance, operation and recycling. It makes a useful LED lights for installation in inaccessible locations, but if such tasks as cleaning a light fixture needed, and light sources can be replaced at the same time, denying protection ‘low’ advantage. EfficiencyAs semiconductor devices, LEDs are very efficient. Current technology allows the device to make them push the limits in excess of standard lighting. Addressing the nature of light produced by LEDs allows design lamps with high efficiency in general. consumptionThe low power low power consumption of LEDs leads to major energy savings that can often drive the installation of LED-based systems. Initial purchase costs go higher, but it can be proven return on investment cost in a short time. BrightnessLight results are constantly growing, and there are some products that have a higher output than traditional lighting lumen. HeatLEDs not produce heat in the form of infrared radiation (IR), unlike inkandeshente lamps, making them hot to the touch. This lack of heat allows LED fixtures to be used in locations where heating from conventional sources would cause a particular problem eg lights food, textiles, objects, etc. However, LEDs do not produce heat in the semiconductor junction inside the device and good thermal management must be employed in high power devices to maintain operation lifeCostIn many applications, LEDs are more expensive in comparison with other light sources, when the measured data such as £ per-lumen “. LED manufacturers continue to work to reduce their production costs while at the same time grow light for their mobile devices. However, the cost high initial LED-based systems is offset by the consumption of lower, lower maintenance costs and other factors. initial rates may seem high, but consider that the use of electricity will be saved, they pay for themselves. electricity savings to spend on direct replacement LED lamp LED lamp halogen 75W vs bulbs10W to compare prices Small Form-factorsLEDs are very small – a typical high brightness LED chips measure 3 0 0 mm by 3 mm, while the strong components can be 1 mm x 1 mm or greater. There are many examples where the availability of small, high-brightness devices enabled significant market advancement. A clear example is the mobile phone handset, where blue, green and white LEDs now used in models and keypad back light liquid crystal display (LCD) screens. The immediate switch-onLEDs the fast, even when it’s cold, and this is a particular advantage for certain applications such as vehicle brake lights. ColourLEDs are available in a wide range of bright, saturated colors (though the performance of different spectrum), and white devices are also available. Modules that contain different color LED (usually red, green and blue, or RGB) can be tuned for a wide range of colors and light side dimmed. RGB modules offer a much wider range of colors from white LEDs or other traditional sources of white light, which is a particular advantage in applications such as backlighting liquid crystal displays (LCD’s). LED RGB and color characteristics mixingLED change with time, temperature and currents, and from device to device. For RGB LEDs, the performance of different colors on different devices changes in prices. This can lead to variations of lighting color and intensity, and poor reproducibility. LED vs Halogen LED Lighting Types Now, LED bulbs are widely used in homes, offices, roads, shops, park, etc. for decoration and lighting LED lighting family mainly includes: an LED lamp2 top. LED lamp3 country. LED lamp4 field. Light5 LED tubes. LED rope lamp6. Lamp7 LED pool. lamp8 LED curtain. LED Christmas (Festival) lamp9. LED ceiling lamp10. light11 LED street. LED Solar lightEtc. In a word, LED lighting will be the future of lighting, and it will definitely replace the halogen light in the near future.