Diode light, or better known as LED (light-emitting diode) is a semiconductor that emits incoherent monochromatic light when given a forward voltage.
These symptoms include elektroluminesensi form. Color produced depends on the semiconducting material used, and can be near ultraviolet or near infrared.
Function LED
LED semiconductor diode is a kind of special. Like a normal diode, an LED consists of a semiconductor chip which is fully charged, or on-light bulb, with impurities to create a structure called a pn junction. Charge-carriers - electrons and holes flow into the junction from electrodes with different voltages. When an electron meets a hole, he fell into a lower energy level, and release energy in the form of photons.
Light emission
The wavelength of light emitted, and therefore its color, depending on the difference in energy band of material forming a pn junction. A normal diode, typically made of silicon or germanium, emits visible light near infrared, but the material used for an LED have a difference between the energy band near infrared light, visible and near ultraviolet.
LED Circuit
LED circuits can be designed in a way set the LED in series or parallel position. When arranged in series, hence the need to consider is the amount of voltage needed all the LEDs in this circuit. But when the LED is placed in parallel circumstances, then one should pay attention to the amount of current required throughout the LED in this circuit.
Putting LEDs in series circuit would be more difficult because each LED has a forward voltage (Vf) are different. This difference will cause if the amount of voltage supplied by the source of electrical power is not sufficient to generate the LED chip, then some of the LED will not light up. Conversely, when the applied voltage is too large will result in damage to the LEDs which have a relatively low forward voltage.
In general, LED wants to be prepared in a series must have the same forward voltage, or at least did not differ greatly so that this LED circuit can work properly.
Polarization
Unlike incandescent and fluorescent lamps, LEDs have a tendency of polarization. Chip LED has a positive pole and negative (pn) and will only illuminate if given forward current. This is because LEDs are made from semiconductor materials that will only allow electric current to flow in one direction and not in the other direction. When given current LED reverse, there would be only a little current through the LED chip. This causes the LED chip will not emit light.
Chip LEDs typically have a relatively low voltage damage. When a given voltage a few volts to the upside, usually unidirectional nature of the insulator will break causing LED current can flow in the opposite direction.