Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Module 4 - Electronic Fundamentals > 4.1 Semiconductors > Flashcards

4.1 Semiconductors Flashcards

1
Q

What is a chemical compound?

A

A chemical combination of 2 or more elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many known elements are there?

A

Over 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the smallest part of a compound which retains all of the compounds characteristics called?

A

A molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What part of an atom has a negative charge?

A

An electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What part of an atom has a positive charge?

A

A proton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the mass of a proton?

A

1827 x bigger than an electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What part of an atom has no electric charge?

A

A neutron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the principle to predict the number of electrons in a shell?

A

Pauli’s Principle = 2n ^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the major shells of an atom?

A

K, L, M… etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What can the major electron shells of an atom be divided into?

A

Sub shells

s, p, d and f

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a valence shell?

A

The outer shell of an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a valence electron?

A

An electron in the outer shell of an atom (the valence shell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a Quanta?

A

The definite units required to move electrons from one shell to the next highest shell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is ionisation?

A

When an atom gains/loses electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a negative ion?

A

An atom that has gained electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a positive ion?

A

An atom that has lost electrons

17
Q

What is the forbidden band?

A

An energy gap between the conduction band and the valence band where there are no electrons.

18
Q

What is the conduction band?

A

Electrons in this band are easily removed by the application of external electric fields. Materials with many electrons here act as good conductors.

19
Q

What is an electron-hole pair?

A

When an electron moves to the conduction band and leaves behind a deficiency/hole in the valence band.

20
Q

What is a covalent bond?

A

The sharing of valence electrons between two or more atoms. It holds the atoms together in an orderly structure called a crystal.

21
Q

Pure silicon and germanium are what?

A

Poor conductors of electricity, but classed as semiconductors.

22
Q

What is the electron current flow?

A

The movement of electrons in a crystal towards an applied voltage.

23
Q

What charge does the hole in the valence shell have when an electron moves to the conduction band?

A

A positive charge.

24
Q

What is the hole flow?

A

The hole in the valence shell moving towards a negative potential (opposite direction of electron flow).

25
Q

What are intrinsic semiconductors?

A

Semiconductors with no impurities.

26
Q

What is special about the number of holes in an electron-hole pair of an intrinsic semiconductor?

A

They are always equal to the number of conduction electrons.

27
Q

What periodic table group are most semiconductor materials?

A

4a

28
Q

What are the groups in the periodic table of which doping materials come from for semiconductors?

A

3a and 5a

29
Q

What is the ‘favourite’ semiconductor used today?

A

Silicon (Si)

  • abundantly available
  • 8th most common element by mass in the universe
30
Q

What is a tetravalent semiconductor?

A

A pure or intrinsic semiconductor.

31
Q

What are the two types of doped semiconductor materials?

A
  • N-type

- P-type

32
Q

Why is silicon the semiconductor of choice?

A

Ease of processing and more stable temperature characteristics

33
Q

What advantage does germanium diodes have over silicon diodes?

A

Intrinsically low voltage drop, 0.3V meaning low power loss and more efficient diode.
Better in signal detection/FM frequencies and low-level digital circuits.

34
Q

What is the average voltage drop on a silicon diode?

A

0.7V typically,

Module 4 - Electronic Fundamentals (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions