Please explain me - width of depletion layer varies

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SUMMARY

The width of the depletion layer in semiconductor junctions varies inversely with doping concentration and directly with reverse bias voltage. As doping content decreases, the depletion width increases due to reduced charge neutralization, contrary to common assumptions. In reverse bias conditions, the depletion width expands; however, in a thyristor's forward blocking state, increasing voltage at the J2 junction leads to a decrease in depletion width due to local voltage dynamics. These principles are critical for understanding semiconductor behavior in various applications.

PREREQUISITES
  • Understanding of semiconductor physics, particularly junction theory
  • Familiarity with doping concentrations in p-n junctions
  • Knowledge of reverse bias and its effects on depletion regions
  • Basic concepts of thyristor operation and voltage dynamics
NEXT STEPS
  • Study the relationship between doping concentration and depletion width in p-n junctions
  • Research the effects of reverse bias on depletion regions in various semiconductor devices
  • Learn about thyristor operation, focusing on forward blocking states and junction behavior
  • Explore advanced semiconductor physics resources, such as "Semiconductor Physics and Devices" by Donald A. Neamen
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Students and professionals in electrical engineering, semiconductor researchers, and anyone interested in the operational principles of p-n junctions and thyristors.

abhishek91
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please explain me -- width of depletion layer varies

hey guys,
i need to know how does width of depletion layer varies with various factors and i have mentioned all my queries below
1.first of all i want to know how does width of depletion layer increases with decrease in doping content??as per my knowledge when p and n regions r combined to form a junction electrons from n region and holes from p region move to p and n regions respectively leaving behind immobile charges and from this we can conclude that as the doping content increases width should decrease but opposite of this actually happens.why and how?
2.when we increase the potential drop in case of reverse bias, width of depletion layer increases but in case of thyristor when it is in forward blocking state and we increase the voltage the width of j2 junction which is reversed biased decreases that's what given in md singh and khanchandani. how does all this happen..please someone explain this ...
thanks
 
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Semiconductors 101:

http://en.wikipedia.org/wiki/Depletion_region

1. Increasing doping causes neutralization to occur "sooner" in distance ergo smaller width, and vice versa.

2. The voltage is relative to other junctions - locally it is less reverse biased.
 

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