Why making an LED is like baking a pizza

26 Oct

LED lighting and other electronics have been revolutionised by the elements Gallium and Indium. These are versatile soft metals that sit above one another on the periodic table and have unique properties that have been harnessed to develop semi-conductors that are used in the LED industry.

A semiconductor material has an electrical conductivity value falling between that of a conductor, like copper, gold, etc. and an insulator, such as glass. Their resistance decreases as their temperature increases, which is behaviour opposite to that of a metal. Their conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities (“doping”) into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created.

Gallium and Indium are used in the semi-conductor process, due to their conductive properties. Also known as earth III-V materials, due to their position on the periodic table, that can be combined with other elements and applied to a substrate surface (eg. Glass) in layers, a bit like making a pizza. You start with a base (substrate, like glass), elements like Gallium and Arsenic are applied to the surface and heated up (baked). They combine (cheese melts) and Gallium Arsenide is made.

These elements can be layered to give different results – gallium arsenide is used in production of lasers. A combination of Gallium, Indium and Nitrogen in a compound semiconductor, will work in the shorter part of the optical spectrum (blue/UV light). This combination is the essence of LED lighting.

The individual elements within the group will have different electronic and optical properties, which allows us to make lasers and LEDS. The combination allows us to tune the electronic and optical properties, we can get light in the red part of the spectrum or the UV part of the spectrum or the green part of the spectrum, which is one of the huge advantages of the compound semiconductors.

So, with LED lighting being so efficient, where are we going to see the improvements? In 2010 around 25% of lights sold were LEDs, in 2018 it is closer to 60%. The technological improvements in such a short space of time means that the LEDs are 20 times more efficient than old incandescent fittings and around 4 times more efficient than fluorescent luminaires. There has been a 20% improvement in efficiencies, year on year.

Why is this important?

With 25% of electricity globally being used in lighting, the improvements in efficiency can significantly reduce electricity consumption and allow us to help tackle climate change.

Of the 25%, it is feasible that 80-90% of that could be saved by changing to LEDs.

For more information or to request a meeting call Aidan Brown on 01242 250633 or email: info@ledindustriallighting.co.uk