please explain me -- width of depletion layer varies

abhishek91

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 thats what given in md singh and khanchandani. how does all this happen..please someone explain this ...
thanks

jsgruszynski

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.