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How depletion region get thin by increasing doping level in a zener diode?
Answer A diode is basically a PN junction device. P type semiconductors are rich in holes while N types are rich in electrons. (Rich means majority carriers here, wh…ich are found in the outer shell of atoms). Thus at the junction of this P and N type material, electrons and holes will combine resulting in a deficiency of charge carriers. This is termed the depletion region. When you attach the negative terminal of a battery to the N end of the diode and the positive terminal to the P end, the electrons will be repelled towards the junction and holes too will move towards the junction region, making it thin (narrow) (Further increase in voltage will make current to pass through). The opposite occurs when they are connected the other way. The region becomes thin. For normal operations, zener diodes are connected in reverse (diodes usually are connected reversely unless you want drop some voltage) the depletion layer widens, as described above. But at a certain reverse voltage, the zener starts to conduct suddenly. This is called avalanche/breakdown voltage. How the layer becomes thin (if at all, seems improbable) when they are reverse connected, I do not know.
Answer Doping is a process of mixing sum impurity in a iinsulator and then that acts like conductor...The materials which are said to behave like this are called… semi conductor . it is very often to know that when we add some impurity ,the bonding inside the semi conductor just breaks and rejoins itself with new commer electrons of the impurity...major semi conductors are GaAs,Si,Ge ...we can notice out that if 1 electron is added to silicon(si),it reffers to a conductivity of 10 million electrons...so just think of this example,when we add extra impurity...what would happen?????????resulting a great vacancy for electrons to continueue their activities. Coming to depletion region...it is just a smaal region where ions are formed + on N types and - to P Types .though it is very small but it cannot be neglected ....Hence we improve the ratio of impurity added.....the free electrons available are also in a huge number so a litttle space for the Depletion region remains there but it never ends....i-e depletion region can not be removed finally
A Zener diode is a type of diode that sends current in the forward way like a normal diode, but also in the reverse direction if there is voltage that is larger than the break…down voltage which is also known as "Zener voltage". The apparatus was named after Clarence Zener, who discovered this electrical property.
zener diode is for regulator purpose. it will maintain the constant voltage so we are using as regulator. we have to connect reverse bias then only it will act like zener diod…e if we are connecting forword bias it will act like normal diode.............. H.L.Kiran
A diode (some people incorrectly call them rectifiers) is a semiconductor device that allows a current to flow in one direction. A Zener diode allows a reverse to current to f…low at a defined voltage. A common application for them is as a voltage regulator. Named for C M Zener , US Physicist. A zener diode is a diode and like all diodes it will conduct in both directions. If a reversed voltage is applied it will breakdown and conduct current. Most diodes when they breakdown the reversed voltage cannot be predictable. However a zener diode when they do breakdown in the reverse voltage mode that voltage can be made as predictable and remain +/- % of the breakdown voltage. Therefore this steady voltage can be used as a regulator for instance or a definite voltage drop if need be.
so that its depletion layer is narrower... when a high reverse voltage is applied across the junction the electron hole generation takes place.....
Zener diodes are normally operated in their reverse breakdown voltage curve.
A: As voltage in the reverse direction is increased a point will be reached where the zener diode will breakdown an start conducting current therefore any additional input vol…tage across the zener will remain the same
A zener diode (sic) is a semiconductor diode that is designed to have a specific reverse breakdown voltage, and not to destruct when it reaches it. It can thus be wired in ser…ies with a resistor to generate a regulated voltage using the principal of a shunt regulator.
increases with doping
As we bring P type and N type semiconductors fused together, then rich holes in P type would get neutralized with some rich electrons in N type. Hence at the juntion region, t…here will not be charge carriers ie holes and electrons. So it is known as Depletion Region. Depletion means emptying something. In case of ordinary diode this depletion region would be wider where as in case of Zener Diode the depletion region would be narrower. This is because the semiconductors are heavily doped. Hence potential barrier would be easily built up even with a thin region where holes and electrons get combined for neutrelization.
zener resistance of a zener diode is the resistance of the zener diode but which is the resistance of a diode
the area around the junction when not forward biased
The space around the junction of a diode that is not forward biased that is depleted of charge carriers due either to spontaneous electron-hole recombination or the withdr…awal of charge carriers by attraction when reverse biased. Without available charge carriers at the junction the diode is not able to conduct an electrical current. When the diode is biased such that the depletion region vanishes the diode is then forward biased and can conduct an electrical current. The fact that it takes a certain voltage across the diode to eliminate the depletion region is what causes the nonzero knee voltage in diodes.