what exactly do you mean by led ?
What is an led ?
An extremely basic overview of how light-emitting diodes work.
In the most basic terms the simplest way, a light-emitting diode ( led full form) is the semiconductor device that releases illumination when an electric current is moved through it. Light is produced when the particles that carry this current (known as holes and electrons) combine together within this semiconductor substance.
Since light is generated within the semiconductor solid LEDs are referred to as solid-state devices. Solid-state lighting, which also encompasses organic LEDs (OLEDs) is what differentiates this type of lighting from other sources using glowing filaments that are heated (incandescent and tungsten halogen lamps) and gas discharge (fluorescent bulbs).
Different colors
Inside the semiconductor of the LED, the electrons and holes are contained in energy bands. The separation between the bands (i.e. that is the bandgap) determines the energy of the photons (light particles) which are released through the LED.
The photon energy determines the intensity of the light and, consequently, the color. Different semiconductors with different bandgaps emit different colors of light. The precise wavelength (color) is able to be controlled by changing the composition of the light-emitting, or active area.
LEDs are made up of semiconductor compounds, which are made up of elements of group III and group V of the periodic table (these are referred to as III-V-based materials). The most common III-V materials used to make LEDs are gallium arsenide (GaAs) and gallium phosphide (GaP).
The LED market was limited color options and, in particular, commercial blue and white LEDs weren't available. The advent of LEDs that were that were based on the gallium-nitride (GaN) materials system completed the colors available and opened up many new applications.
Main LED materials
The main semiconductor materials used to make LEDs are:
- Indium gallium nitride (InGaN):blue, green and ultraviolet high-brightness LEDs
- aluminum gallium Phosphide (AlGaInP):yellow, orange and red high-brightness LEDs
- Algalium gallium arsenide (AlGaAs):red and infrared LEDs
- Gallium Phosphide (GaP):yellow and green LEDs
Learn About LED Lighting
The Basics of LED Lighting
What are LEDs and how do they work?
LEDstands for light emitting diode. LED lighting products generate light up to 90 percent more efficiently than conventional light bulbs. How do they function? An electrical current is passed through a microchip. This lights the tiny light sources called LEDs. The product is visible lighting. To ensure that the LEDs perform properly the heat generated by LEDs is then absorbed by a heat sink.
Lifetime of LED Lighting Products
The lifespan of LED light sources is defined differently than that of other sources of light, like incandescent and CFL, or compact fluorescent light (CFL). LEDs generally do not "burn out" or fail. Instead, they experience 'lumen depreciation which is when the LED's brightness decreases gradually over the course of. As opposed to incandescent bulbs "lifetime" is established on a forecast of when brightness decreases by 30.
How are LEDs Used in Lighting
LEDs are integrated into bulbs and fixtures for general lighting applications. Small in size, LEDs provide unique design opportunities. A few LED bulb designs might physically resemble traditional light bulbs , and may better complement the look of traditional light bulbs. Certain LED lighting fixtures could include LEDs that are a permanent light source. There are also hybrid solutions where a non-traditional "bulb" or replaceable light source is utilized and specifically designed for an individual fixture. LEDs provide a huge opportunity for innovation in lighting design and can be used in to a greater range of applications than traditional lighting technology.
LEDs and Heat
LEDs use heat sinks to absorb the heat produced by the LED and dissipate it into the surrounding environment. This helps keep LEDs from overheating or burning out. Management of temperature is typically the primary factor in the successful performance of an LED over its lifetime. The more heated the LEDs are operated at, the quicker the light's efficiency will decline and the shorter the time-to-use will be.
LED products utilize a range of innovative heat sink designs and configurations to control heat. Today, advancements in materials have enabled manufacturers to develop LED bulbs that match the shapes and sizes of traditional incandescent bulbs. No matter the heat sink design, all LED products that have been awarded the ENERGY STAR have been tested to verify that they properly manage the heat to ensure that light output is properly maintained through the end of its life rated.
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