• QUESTIONS BEFORE LECTURE 38

now think about these

• What are energy bands in solids, and how do they form?
• What is the Fermi energy?
• What does an energy gap have to do with electrical conductivity?
• Describe and draw the energy band structure diagrams for conductors, insulators, and both kinds of doped semiconductors.
• Name the donor impurity atom for an n-type doped silicon semiconductor.
• Name the acceptor impurity atom for an n-type doped silicon semiconductor.
• Describe and draw a p-n junction. How is it a tiny capacitor? (Recall we described a capacitor in Lecture 11 to understand Maxwell's displacement current.) In what is it used?
• What is the logic of computer code called?
• How does the flow of elctric current at a tiny scale implement this logic?
• What is a chip?
• Compare the damage done to human tissue by neutrons, photons (X-rays), and charged particles.