LED is one of the most common tech terms thrown at you when you go to buy any electronic gadget. Your smart phone, laptop or desktop computer, home lighting, decorative lamps – all are equipped with LED. In this post we will try to understand what is LED, how it works and what its uses are.
Defining LED
LED stands for ‘light emitting diode’. A diode is a semiconductor device with two terminals, which conducts electricity only in one direction. When an electric current passes through this diode, it emits visible light.
Structure of LED
Older LEDs were made from semiconductor material such as gallium arsenide and produced only in a few colors (mainly red or green). Newer LEDs are made from synthetic materials such as p-phenylenevinyl and can produce light of any color. An LED is made up of two elements of processed material called P-type semiconductors and N-type semiconductors. These two elements are placed in direct contact, forming a region called the P-N junction. The shape of this P-N junction is determined by its application. There is a transparent package in this P-N junction which allows visible energy to pass through.
Image Courtesy: www.ucusa.org
How LED Works
When electricity is passed through the diode, atoms within the first material in the semiconductor chip get excited to higher level of energy which needs to be released. As the atoms shed electrons to the other material within the chip, energy is released in the form of photons, which we see as light. This effect is called electroluminescence.
Advantages of LED
LEDs are energy efficient as they need much less voltage and current as compared to a fluorescent bulb with same brightness. At the same time, they are small in size and can be packed together in bundles to generate high levels of brightness and luminosity. LEDs enable faster switching and can be easily controlled and programmed. LEDs have a long lifetime and if installed properly can function for decades. They are highly efficient and reliable due to their resistance to shock and vibration. LEDs are safe as there is no radiated heat or UV Rays.
Applications of LED
LEDs can be used for diverse purposes. General applications include indicator lights, LCD panel backlighting, fiber optic data transmission, remote control, general lighting, traffic signals, camera flashes, advertising signs, and optoisolators. They are also being used for aviation lighting, sensor technology and advanced communications technology.
Related Posts:
Difference between electric charge and electric current