The most common semiconductor material is silicon, largely due to its abundance and efficiency in electronic applications. However, other materials like germanium, gallium arsenide, and silicon carbide are also used in specific applications.
Semiconductors owe their behavior to their atomic structure. In a semiconductor crystal, the atoms are arranged in a regular pattern. At absolute zero temperature, the semiconductor behaves as an insulator, as all the electrons are bound tightly to their respective atoms. However, as the temperature increases, some electrons gain enough energy to break free from their atomic bonds, creating charge carriers-electrons with negative charge and “holes” with a positive charge.
The behavior of these charge carriers determines the conductivity of the semiconductor. By introducing impurities through a process called doping, the conductivity of a semiconductor can be deliberately altered. Doping with an element that has more valence electrons than the host material introduces extra negative charge carriers (n-type doping), while doping with an element that has fewer valence electrons creates extra positive charge carriers (p-type doping).
The junction between n-type and p-type semiconductors forms a diode, a fundamental component in electronics. When a voltage is applied across the diode in the forward bias, it allows current to flow easily, but in reverse bias, it blocks the current. This property is crucial in rectifying current and creating logic gates in electronic circuits.
Semiconductors are the backbone of integrated circuits (ICs) or microchips. These ICs contain billions of transistors—tiny switches that control the flow of electrical current. Transistors form the basis of digital logic and are integral to the operation of computers, smartphones, digital cameras, and almost all modern electronic devices.
The semiconductor industry constantly pushes boundaries, aiming for smaller, more efficient, and powerful devices. Advancements in semiconductor technology continue to revolutionize various fields, including artificial intelligence, telecommunications, renewable energy, and healthcare, among others.