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Flashcards in Band thoery Deck (8):
1

Conduction Band

It is the lowest unfilled band

2

Valence Band

It is the uppermost Band

3

Forbidden Band

It is a range of energies which cannot be occupied bu an electron

4

Intrinsic Semiconductors

It is a substance Such as pure silicon or germanium that at room temperature has a typical resistance between that of metals and insulators

5

Intrinsic semiconductors at 0Kelvin

Valence band is fully occupied
The conduction band is empty
The forbidden band has a width of about 1eV

6

Conduction in a metal

The valence band overlaps the conduction band
Forbidden band does not exist

7

Conduction in insulators

The valence band is fully occupied
Conduction band is empty
Forbidden band is very wide

8

LDR

Photons of light promote electrons from the valence band to conduction band by transferring their energy to electron
Increase in light intensity gives rise to an increase in the number of photons per unit time
Resistance decreases as the intensity of light increases