Semiconductor Materials: What They Are and How They’re Used

Relatively unfamiliar to most people, semiconductor materials - or, more precisely, their scarcity - have been at the heart of the latest crisis affecting the automotive industry.

At a time when cars increasingly rely on circuits, chips and processors, the shortage of semiconductor materials has caused production delays, forced assembly lines to stop, and pushed manufacturers to look for “ingenious” workarounds, such as the solution Peugeot adopted for the 308.

So what exactly are these semiconductor materials whose lack has been driving production shutdowns across the automotive sector, and what are they used for?

Why semiconductor materials are disrupting the automotive industry

Modern vehicles depend more and more on electronic systems, which in turn require a steady supply of chips and other components built using semiconductor materials. When those materials are in short supply, carmakers can be left unable to complete vehicles to schedule, resulting in postponed production, temporary stoppages and improvised alternatives.

What are they?

In the simplest possible terms, a semiconductor material is one that can behave either as an electrical conductor or as an insulator, depending on various factors such as ambient temperature, the electromagnetic field it is exposed to, or its own molecular composition.

Because they occur naturally, several elements in the periodic table can act as semiconductors. In industry, the most widely used are silicon (Si) and germanium (Ge), although others exist, including sulphur (S), boron (B) and cadmium (Cd).

When these materials are in a pure state, they are known as intrinsic semiconductors, where the concentration of positive charge carriers is equal to the concentration of negative charge carriers.

However, the types most commonly used by industry are called extrinsic semiconductors. These are defined by the introduction of an impurity - atoms of other materials, for example phosphorus (P) - through a doping process. Without going into the finest technical details (there are two impurity types, resulting in two semiconductor types, “N” and “P”), doping makes it possible to control their electrical properties and how they conduct electric current.

What are their applications?

If you look around, you will find many objects and components that depend on the “services” of semiconductor materials.

The most important application is the manufacture of transistors - a small component invented in 1947 that sparked an “electronic revolution” and is used to amplify or switch electronic signals and electrical power.

From transistors to chips, microprocessors and processors

This tiny component, made using semiconductor materials, underpins the production of chips, microprocessors and processors found in virtually all electronic devices we live with day to day.

Diodes in the automotive industry: LEDs

In addition, semiconductor materials are also used to produce diodes. In the automotive industry, the most common are light-emitting diodes, widely known as LED (light-emitting diode).

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