The barrier voltage (V0or Vr) in a junction diode is the effect ofa)th...
Due to the density gradient across the junction, holes will initially diffuse to the right across the junction, and electrons to the left. The positive holes which neutralizes the acceptor ions near the junction in the p-type silicon disappears as a result of combination with electrons which have diffused across the junction. Similarly, electrons in n-type semiconductor combines with holes.
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The barrier voltage (V0or Vr) in a junction diode is the effect ofa)th...
The barrier voltage (V0 or Vr) in a junction diode is the effect of:
The correct answer is option 'D': the recombination of charge carriers across the junction leaving behind the opposite charged ions.
Explanation:
A junction diode is formed by bringing together a p-type semiconductor material and an n-type semiconductor material. The p-side is doped with acceptor impurities, creating positively charged holes, while the n-side is doped with donor impurities, creating negatively charged electrons. When these two materials are brought together to form a junction, a depletion region is formed at the interface.
Depletion Region:
The depletion region is a region near the junction where there are no free charge carriers. This region is created due to the diffusion of charge carriers from the p-side to the n-side and vice versa. As a result, positive ions are left behind on the n-side and negative ions are left behind on the p-side, creating an electric field that opposes further diffusion.
Barrier Voltage:
The barrier voltage, also known as the built-in potential (V0 or Vr), is the voltage difference across the junction that arises due to the presence of the depletion region. This voltage is necessary to maintain the equilibrium of charge carriers in the diode.
Recombination of Charge Carriers:
The barrier voltage is primarily the result of the recombination of charge carriers across the junction. When a positive hole from the p-side and a negative electron from the n-side come close to each other within the depletion region, they can recombine. This recombination process leaves behind positively charged ions on the n-side and negatively charged ions on the p-side.
Effect of Recombination:
The recombination of charge carriers creates a region near the junction with a net positive charge on the n-side and a net negative charge on the p-side. This results in the formation of a potential difference, known as the barrier voltage, which opposes the further flow of charge carriers across the junction.
Conclusion:
In summary, the barrier voltage in a junction diode is primarily the result of the recombination of charge carriers across the junction. This recombination process leaves behind oppositely charged ions, creating a potential difference that acts as a barrier to the flow of current in the reverse biased condition of the diode.
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