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How depletion width varies with biasing voltage?
when the diode is applied forward bias voltage the width of depletion region gets reduced the barrier voltage decreases there by facilitating the easy exchange of holes and electrons. when the diode is reverse biased the width of depletion region increases there by hindering the flow or exchange of charge carriers.
What happens in the depletion region in reverse bias?
in forward biasing depletion region width decreases and in reverse biasing it increases .
Why Reduction in Depletion region width with increase in doping?
Because Reverse bias constrained the majority carries to repel from both side (P side & N side)hence Depletion layer is formed with a large extant of majority carriers hence the depletion region is wider in reverse bias.
Why diode acts as insulator in reverse biasing?
a diode has two junctions one is doped with p-type and another is doped with n-type.a diode connected in reverse bias means that the n-channel is connected to the positive end of the battery and p-channel is attached to the negative end of the battery if we start increasing the reverse voltage the width of depletion region increases and the exchange of charge carriers (holes and electrons) is inhibited so we expect zero current in the circuit but on experimental observations we had confirmed that a small current (micro-amp) is observed due to the minority charge carriers(electrons in p-channel and holes in n-channel) present in the diode , for these minority charge carriers the applied voltage appers as as forward bias to them so they conduct . but on further increasing the reverse voltage we note a large change in the reverse current this is due to junction breakdown (the depletion region is broken , so there is no demarcation between p-channel and n-channel in the diode). the voltage at which this phenomena occurs is called 'break-down voltage'
When both junctions of npn diode are reverse biased?
When p-n junction of a diode reversed biased then majority carriers are not able to cross the junction and are attracted in respective regions.So current becomes approximately zero.But because of minority carriers a reverse current keeps flowing.It is called Reverse Saturation Current.And due to attraction towards sides,charges go away from junction.So width of depletion reason increases.
How depletion width varies with biasing voltage?
when the diode is applied forward bias voltage the width of depletion region gets reduced the barrier voltage decreases there by facilitating the easy exchange of holes and electrons. when the diode is reverse biased the width of depletion region increases there by hindering the flow or exchange of charge carriers.
What happens in the depletion region in reverse bias?
in forward biasing depletion region width decreases and in reverse biasing it increases .
What is the thickness of the depletion layer in a semiconductor?
The thickness of the depletion region or depletion layer (and there are other terms) varies as the design of the semiconductor. The layers in a semiconductor are "grown" (usually by deposition), and this can be controlled. The typical depletion region thickness in an "average" junction diode is about a micron, or 10-6 meters. Junction "construction" presents major engineering considerations to those who design and make semiconductors as there are many different kinds. A link is provided to the section on the width of depletion regions in the Wikipedia article on that topic.
What is breakdown voltage of diode?
The critical value of the voltage, at which the breakdown of a P-N junction diode occurs is called the breakdown voltage.The breakdown voltage depends on the width of the depletion region, which, in turn, depends on the doping level. The junction offers almost zero resistance at the breakdown point.
What is meant by transition and space charge capacitance of a diode?
space charge region in a diode or say a bjt for better understanding is same as the depletion region, both transition capacitance and depletion capacitance are the same c= (epsilon*A)/d ; where ... c is capacitance A is area and d is the depletion width the other type of capacitance is the diffusion capacitance c= (T*I)/(n*V) where ... c is the capacitance T is transition ti me I is the drift current n is emission coefficient ... its value is 1 for germanium and V is thermal voltage .. 26mv
How temperature effects depletion layer width?
as the temperature increases the width of depletion layer decreases
What effect of depletion layer by biasing?
on forward biasing width of the depletion layer decreases whereas on reverse biasing the width of depletion layer increases.
Does depletion region width becomes zero?
Exactly in forward bias wen internal barrier potential is compensated by external voltage.,
If the impurity concentration is increased how the depletion width effected?
depletion layer decreases
Why Reduction in Depletion region width with increase in doping?
Because Reverse bias constrained the majority carries to repel from both side (P side & N side)hence Depletion layer is formed with a large extant of majority carriers hence the depletion region is wider in reverse bias.
Why diode conducts current in forward bias but does not conduct in reversed bias?
diode current flows only when the diode is forward biased because in reverse bias the barrier potential increases. Diode can conduct in reverse bias if applied votage is high enough to overcome the reverse bias barrier potential but it can be destructive.
How depletion region is narrowed during forward biasing?
When the pn junction is forward biased, some of the space charge is neutralized reducing the width of the pn junction.
