What are the two common semiconductors used in a solid state device?

The two common semiconductors used in solid-state devices are Germanium and Silicon. These materials have favorable electrical properties that make them suitable for creating diodes, transistors, and other components used in electronics.

Silicon, in particular, is the most widely used semiconductor in the industry due to its abundant availability, robust thermal and chemical stability, and excellent electronic properties. Germanium, while less common than silicon, was the first material used in transistors and has higher electron mobility, which can enhance device performance in certain applications.

In contrast, other materials listed in the options do not serve the same primary role as semiconductors. Carbon in its various allotropes, such as graphite and diamond, is not typically a semiconductor. Copper and Silver are conductors, while P-type and N-type refer to the types of semiconductor doping rather than the semiconductor materials themselves. Hence, the pairing of Germanium and Silicon precisely aligns with the commonly utilized materials in electronics for solid-state devices.