Semiconductor & PN Junction Flashcards
The best electrical conductors are…….
silver, copper and aluminum
The atom of a material used as a conductor generally contain _______.
1 or 2 valence electron
Solid-state devices, such as diodes and transistors, are often called
Semiconductor
The word _________ refers to the type of material used to make solid-state devices.
Semiconductor
An atom that has only one valence electron makes the best conductor because the electron is held loosely in orbit and is easily given up for current flow. True or False
True
How many valence electron does insulator have?
7 to 8 valence electron
How many valence electron shall be consider semiconductor?
4 valence electron
What are the most common semiconductors materials used in the electronics field?
- Germanium
- Silicon
When molecules arrange themselves into a crystal structure with a definite pattern. This pattern is called _______.
Lattice structure
When pure semiconductor material is mixed with an impurity that has only three valence electrons, such as indium or gallium, _________
the lattice structure changes, leaving a hole in the material
A semi-conductor material with a net positive charge are known as a ___________.
P-type material
A semi-conductor material with a net negative charge are known as a ___________.
N-type material
How is a P-type material made?
When pure semiconductor material is mixed with an impurity that has only three valence electrons, the lattice structure changes, leaving a hole in the material. The hole, which has taken place of an electron, has a positive charge
How is a N-type material made?
When a semiconductor material is mixed with an impurity that has five valence electron, the lattice structure has an excess of electrons meaning that the material has a net negative charge. t
Which type of semiconductor material can withstand the greatest amount of heat?
Silicon is used more often because of its ability to withstand heat.
how the PN junction (diode) produced?
A PN junction is produced by joining p-type and n-type semiconductor materials.
Solid-state devices are made by______________ materials
combination P-type and N-type
How does diode operates in circuit?
What is doping
An outer orbits of the atoms of material are filled or almost filled with valence are known as _______.
Insulator
What is Semiconductor?
elements have exactly four valence electrons and are therefore considered neither good conductors nor good insulators.
Why silicon use more often?
Its ability to withstand heat.
The two common semi conductor are:
- Germanium
- Silicon
Germanium diodes have a lower forward voltage drop about _______.
0.3 volt
What is covalent bonding?
Atoms share electrons to fill their valence shells. Each shared pair of electrons constitutes a covalent bond
The atoms of purified semiconductor materials arrange themselves into a unique pattern known as a
Crystal-lattice structure
The atoms of the impurity are injected into the crystal through a process know as
Doping
An N-type semiconductor is formed when an impurity having five valence electrons is introduced into the pure semiconductor crystal. This impurity is said to be______
Pentavalent
when a semiconductor material is mixed with an impurity that has five valence electrons, such as arsenic or antimony, the lattice structure has an ______
Excess of electron. meaning that the material has a net negative charge which is N-Type
All solid-state devices are made from combination of _
P and N-type material
How do you determine type of devices?
The number of layer of material and the thickness of each layer
Diode is often called a __________ because it is made by joining a piece of P-type material and a piece of N-type material
PN junction
what device is made by join three layers of semiconductor materials
Transistor
What is a rectifier?
A rectifier is a device that changes, or converts, AC voltage into DC voltage.
A positive voltage connected to anode is known as which bias?
Forward bias
What are the two types of rectifier are:
Half-wave and Full-wave
How many diodes are required to construct the bridge rectifier?
4 diodes
An P-type semiconductor is formed when an impurity having three valence electrons is introduced into the pure semiconductor crystal. This impurity is said to be______
Trivalent
Semiconductor are not easily destroyed by heat? True or False?
False, semiconductor is easily destroyed by heat
It is VERY IMPORTANT to operate semiconductors within their
Voltage, current and temperature limits
If the ohm meter indicate very low resistance, the diode is_________.
forward bias
If the ohm meter indicate very high resistance, the diode is_________.
reversed bias
when using a multi-meter on the diode checker, what value does the meter read if the diode is good?
600mV
The half-wave rectifier can be constructed using only_________.
one diode
As the temperature increases, the resistance _________. So the conductivity ____________.
Decrease, increase
What is the purpose of have heat sink?
To improve the dissipation of heat because of internal R losses in semiconductor devices such as diodes and transistors
The voltage drops for germanium is _________.
0.3 V
The P-type material gains some electrons (negative charge), and the N-type material loses some electrons (positive charge). Therefore, a small __________________ is formed at the junction.
Barrier Potential
What element is mixed with impurity that has only three valence electrons.
Indium or gallium
What element is mixed with impurity that has only five valence electrons.
arsenic or antimony
A diode is NOT made by joining piece of P-type material and a piece of N-type material together. True or false?
False.
What is a term “avalanche”
3 significant rating for rectifier diodes are
- forward current voltage
2.
