Semiconductor materials are substances that have electrical conductivity between that of conductors and insulators. They are essential in modern electronics, as they can be manipulated to control electrical current. Common semiconductor materials include silicon, germanium, and gallium arsenide. These materials are often used in devices like transistors, diodes, and solar cells. The unique properties of semiconductors arise from their atomic structure, which allows for the addition of impurities, a process known as doping. This process enhances their conductivity and enables the creation of p-type and n-type semiconductors, which are crucial for building integrated circuits and other electronic components.