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leojun
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what happens to the minor charge carriers in p-n junction diode when forward biased?
If they reach the depletion region, they will either diffuse across the junction to the region where they are the majority carrier, or they will recombine.leojun said:what happens to the minor charge carriers in p-n junction diode when forward biased?
The minor charge carriers in a p-n junction diode are electrons and holes. When a p-n junction diode is in equilibrium, the number of electrons and holes is equal on both sides of the junction. However, when the diode is forward biased, the majority carriers (electrons in n-type and holes in p-type) flow through the junction while the minority carriers (holes in n-type and electrons in p-type) are pushed away from the junction and into the depletion region.
The presence of minor charge carriers affects the conductivity of the p-n junction diode. When the diode is forward biased, the flow of majority carriers results in a higher conductivity, while the presence of minority carriers in the depletion region decreases the conductivity. This results in a lower voltage drop across the diode and allows for current to flow through it.
The depletion region is an area near the junction where the majority carriers have diffused across the junction and combined with the opposite type of carriers, leaving behind an area depleted of free charge carriers. This depletion region acts as a barrier to the flow of minority carriers, allowing for the diode to function as a one-way valve for current.
At higher temperatures, the number of minority charge carriers increases, which results in a decrease in the barrier potential of the p-n junction diode. This means that the diode will have a lower threshold voltage and will conduct more easily. Conversely, at lower temperatures, the number of minority carriers decreases, resulting in a higher barrier potential and a higher threshold voltage for the diode to conduct.
Recombination refers to the process of the majority and minority carriers combining and neutralizing each other's charge. In a p-n junction diode, the recombination rate of minor carriers is lower compared to that of the majority carriers. This is because the majority carriers have a higher concentration and are more likely to combine with the minority carriers in the depletion region, resulting in a lower overall recombination rate.