Germanium and Silicon are the materials used as:

Explanation

Germanium and silicon are primarily used as semiconductors in various electronic applications. They are essential materials in the semiconductor industry for manufacturing transistors, diodes, integrated circuits (ICs), and other electronic devices.Both germanium and silicon have properties that make them suitable for this purpose. They can be doped with specific impurities to modify their electrical conductivity, allowing them to act as either n-type or p-type semiconductors. This capability to conduct electricity under certain conditions and insulate under others is fundamental for their role in electronic components and circuitry.