The simple answer is that an LED is a type of light. It’s also a type of diode. The acronym LED stands for Light Emitting Diode.
Just as a diode is a semiconductor, an LED uses semiconductor properties to allow it to illuminate – unlike an incandescent light which uses a filament that heats up to extreme temperatures to illuminate which is very inefficient.
LEDs are small, efficient, and cheap which make them very appealing to use in electronic products compared to other lighting devices of yesteryear.
Having a small footprint means that there’s less space and less material to use in creating products – being efficient means there’s less waste in energy in the form of heat for devices, which is always something highly sought after – and being cheap is, well, what everyone wants for a price of something.
What Is a Diode?
A diode is a two-terminal semiconductor device that allows the flow of current in one direction. It carries current when its voltage is positive and no current when its voltage is negative.
A diode is considered a PN junction – meaning that it’s partly-made of a positive-type semiconductor material (P), and is partly-made of a negative-type semiconductor material (N). When oriented in its forward-bias direction, it allows the flow of current through it. When oriented in its reverse-bias direction, it blocks the flow of current.
How Can a Diode Produce Light?
An LED, like a diode, is made of two materials that are placed close together. One material is usually a metal, such as aluminum – the second material is usually a combination or compound of materials, such as gallium arsenide (GaAs).
The makeup of these materials allow them to emit and absorb electrons when an electric potential is applied across the LED’s terminals. When properly biased, electricity is allowed to flow through the LED and the process of emitting and absorbing electrons between the two materials produces light.
Efficiency of LEDs
Remember earlier that it was mentioned that a diode produces light by having two materials in its makeup that allow it to emit and absorb electrons to produce light? This process makes the LED highly efficient.
Unlike incandescent light bulbs that use resistive tungsten wire that produce extreme heat for lighting, the LED does not use heat to produce light. An LED efficiently uses electricity to create more photons to produce light, therefore reducing a significant amount of energy loss.
Details of an LED Using Its Datasheet
Now we’ll take a look at a specific LED to understand a little bit about it and what its capabilities are. For the following, I chose a 5mm (millimeter) orange diffused LED manufactured by QT Brightek (QTB). We’ll obtain all the information that we’ll cover over this LED through its datasheet, which you can download for yourself below.
