Lecture 3

Question 1

electron

Answer 1

Acts as a particle and wave

Question 2

Conduction band

Answer 2

Region where electricity can flow through Si at heated temperature

Question 3

Energy band structure for Si at T=0K

Answer 3

All electrons are in the valence band

Conduction band is empty

Eg = 1.1eV

Si acts as an insulator

Question 4

Eg

Answer 4

Energy band gap of material (between bottom of conduction band and top of valence band)

Question 5

Energy band structure for Si at T=300K

Answer 5

Some (a few) electrons will be excited to conduction band

Will act as a semiconductor

One covalent bond is broken (can treat the empty state as a +particle called a hole)

Electron moves throughout the material once excited

Question 6

Hole

Answer 6

Missing valence electron in the covalent band treated as a +particle

Represents a missing electron in the valence band

Question 7

Eg - metals

Answer 7

0eV

Good conductors

Question 8

Eg - semiconductors

Answer 8

1-3eV

Question 9

Eg - insulators

Answer 9

~5eV

Question 10

Charge of hole

Answer 10

+e = +1.6*10^-19 C

Question 11

Effective mass

Answer 11

Contains all the internal forces