How are LEDs made and what are they made of? 

LEDs have been around since the 60s and have since grown in popularity and demand due to their affordability and efficient use of energy. 

Ever caught yourself wondering how LEDs are made? and what they are made of? Stick with me as we journey through the world of Light Emitting Diodes, or LEDs for short, the materials involved in their creation, and the intricate processes they undergo to create the most energy-efficient light on the market!

LEDs vs traditional lights (What’s the difference ?)

LEDs, incandescent, and fluorescent lights produce light in different ways, which means they differ in design and mode of operation. 

Traditional lights produce light by passing an electric current through a wire until the wire is hot enough to emit light. In LEDs, things are not that simple. 

LEDs produce light by passing an electrical current through a semiconductor, resulting in a light that emits less heat and is energy efficient. 

LED Materials: what are LEDs made of?

By definition, LED refers to light emitting diode, which means they are made up of small diodes created from semiconductor materials. The trick is to have varying levels of electrons in each layer of a diode, so one layer may have depleted electrons while the other will have excess electrons. 

The imbalance in electron levels across layers of a diode enables them to move between layers in a way that creates light, also known as electronic excitation. 

The semiconductor used in LEDs is made up of crystalline materials that require impurities to serve as electrical conductors. 

At a later stage of manufacturing, the impurities earlier discussed are introduced. It is also important to note that the impurities we speak of are not imperfections by any definition. 

The presence of impurities enhances the value of the diode, in a process known as DopingDoping is essential in the manufacturing of LEDs. The most common impurities added are zinc and nitrogen.

After adding impurities, the final stage is to integrate the wires that allow current to flow through the semiconductors. Gold and silver compounds are often used in LED wires due to their high tolerance for heat while being soldered. Then the diodes are encased in a transparent plastic material, which makes them more durable than traditional bulbs.  

The Design Stage

The design of LEDs is greatly influenced by factors such as the size of the diode, the semiconductor material used, the types of impurities added, and the thickness of diode layers. The color temperature and brightness are all predetermined before the actual manufacturing begins. 

Manufacturing: How LEDs are Made

The LED manufacturing process is a delicate one. It starts with the preparation of the semiconductor materials or wafer. We’ll do our best to leave helpful references just in case some terminologies fly over your head. 

As earlier stated, the manufacturing starts with a semiconductor wafer, by the time the wafer has been prepared, it is then “grown” in a high temperature, high-pressure chamber. 

After the growing process elements such as phosphorous, arsenic, and gallium are purified and introduced into the chamber, which liquifies the concentration. When mixing is complete, a rod is placed in the solution and slowly pulled out. 

The idea is to get the solution to crystallize at the end of the rod, forming a long cylindrical ingot. 

The next stage is the slicing stage, here the material from the previous process is sliced into silicon wafers, then sanded until the surface is smooth. After sanding, the smooth silicon wafer is then dipped into a solution that removes dust, organic materials, and dirt. 

Next, extra layers of semiconductor are added to the wafer, which also introduces impurities or dopents.

Next, metal contacts are placed on the conductor, the placement takes into account whether the diode will be used individually or with others.

Finally, the diodes need to be powered, at this stage wires are attached and the diodes are encased in a glass-like material. That’s how LEDs are made!

Related Questions

What plastic is used to make LEDs?

Polycarbonate (PC) plastics are naturally transparent amorphous thermoplastics.  

Polycarbonate (PC) plastics are used in the manufacturing of LEDs. They are naturally transparent amorphous thermoplastic.

PCs are available in a variety of colors (perhaps translucent and perhaps not), they possess similar characteristics to glass, which means they allow internal transmission of light.

Polycarbonate polymers are particularly useful when impact resistance and/or transparency are a product requirement. (e.g. in bullet-proof glass). 

Products such as plastic lenses in eyewear, medical devices, automotive components, protective gear, greenhouses, Digital Disks (CDs, DVDs, and Blu-ray), and exterior lighting fixtures are mostly made with Polycarbonate polymers. 

It is also possible to combine PC with flame retardant materials without significant material degradation, due to its heat resistant attribute. 

Are LED lights made of plastic?

Yes, LEDs are encased in plastic materials to enhance durability.

Which metal or nonmetal are used to make LED?

Gallium is one of the metals used in LED semiconductor technology. After the growing process elements such as phosphorous, arsenic, and gallium are purified and introduced into the chamber, which liquifies the concentration. Gallium is the first and primary element used in the manufacture of almost all semiconductor LED devices.