Ionization in silicon creates what?

• A. Free electrons
• B. Free holes
• C. Neutron emission
• D. Protons

Answer: (A)

Ionization in silicon means electrons gain enough energy to jump from the valence band into the conduction band. When this happens, a free electron appears in the conduction band, and a hole—the absence of that electron—remains in the valence band. This pair of charge carriers enables current flow. In many contexts, the free electron is highlighted because electrons in silicon typically have higher mobility than holes, making them the dominant contributor to conduction after ionization. Of course, the creation of holes accompanies the process, but the key outcome is the generation of a mobile electron in the conduction band. Neutron emission and protons are not involved in this electronic ionization.