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In wikipedia there are topics, branches of knowledge about diodes. Article gives sometimes brief, sometimes sufficient explanations of the physical phenomena. We concentrated on principle physical phenomena rather than taking into account history and engineering applications.
In electronics, a diode is a two-terminal electronic component with asymmetric conductance; it has low (ideally zero) resistance to current in one direction, and high (ideally infinite) resistance in the other.
A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals.
Further questions T1 (occurred after wikipedia search)
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An ideal diode is a conductor in one direction and an insulator on the other, though in reality we do not seem to have a ‘perfect’ state. The reason that a
PN a PN junction diode conducts in one direction is because of the following. A PN junction diode has two parts the “p” and the “n” side. with excess of holes and electrons respectively. Initially a momentary conduction causes flow of electrons from the “n” and holes from “p” to the opposite side to occur but will stop soon because of electrostatic field that will be created. In the middle of this field a neutral space is created, which is called a depletion layer. Now whenever conduction is required, connection is made so that negative terminal is connected with the “n” side and positive to the “p” side; this will create repulsion which will break the neutral depletion layer and conduction occurs. This connection is called forward bias. On the other hand if positive terminal is connected to “n” side the charges will be pulled away from the neutral zone away. the depletion layer widens and the diode acts as an insulator. this connection is called reverse bias. as shown in the sketch
What is valence band and conduction band?
Valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature.
Conduction band quantifies the range of energy required to free an electron from its bond to an atom. Once freed from this bond, the electron becomes a 'delocalized electron', moving freely within the atomic lattice of the material to which the atom belongs. Various materials may be classified by their band gap: this is defined as the difference between the valence and conduction bands.
How semiconductors make up P and N type?
Conduction of a material is highly dependent on the most external free electrons. Silicon as a typical semiconductor materials has full outer most electrons. When materials other substances are added as impurity conduction property changes. this adding of impurities is known as doping. When a silicon is doped with phosphorus extra electrons which can move freely through the silicon bonds emerges. The result is known as N-type material. On the other hand when a silicon is doped with substances such as germanium; a substance which has extra ‘hole’ in its outermost electron orbit. The resulting material is called a P type.
How does PN junction work?
There are free electrons on N-type, free holes on P-type . when bring them together and join them to make one piece of semicondectorsemiconductor, we can see free electrons -side and free holes on the p-side can initially wander across the junction.When near the junction jump from N to P, holes near the junction jump from P to N . This phenomenon creates a space charge region This movement of electrons and holes in space region gives rise to diffusion current .Now the current flows across the circuit and this current is called the drift current. In this process the current flowing through the PN junction is very high and ultimately the PN junction gets damaged due to overheating caused by the excess flow of current .
Why is there depletion?
Depletion is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have diffused away, or have been forced away by an electric field. It is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current.No free electrons exist on the N side in the depletion region and no free holes exist on the P side .
What is valence band and conduction band?
Valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature.
Conduction band quantifies the range of energy required to free an electron from its bond to an atom. Once freed from this bond, the electron becomes a 'delocalized electron', moving freely within the atomic lattice of the material to which the atom belongs. Various materials may be classified by their band gap: this is defined as the difference between the valence and conduction bands.
What is diode reverse-recovery effect?
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- Do all semiconductor diodes emit light?
- Why semiconductor diodes are widely used instead of other types of diodes?
How
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semiconductors make up P and N type?
Conduction of a material is highly dependent on the most external free electrons. Silicon as a typical semiconductor materials has full outer most
electrons. When materials other substances are added as impurity conduction property changes. this adding of impurities is known as doping. When a silicon is doped with phosphorus extra electrons which can move freely through the silicon bonds emerges. The result is known as N-type material. On the other hand when a silicon is doped with substances such as germanium; a substance which has extra ‘hole’ in its outermost electron orbit. The resulting material is called a P type
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Diodes contain magic smoke.
What is the difference between diode and laser diode?
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