(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A semiconductor diode is made of acceptor and donor dotted regions. In equilibrilum there is a volume charge region at about x = 0. In that region there is no free charge carriers, only single charged. In x<-dp and x > dn, there is no charge at all. The surface area of the diode is A. And the semi conductor material has the permetivity ε. The volume charge distribution is for p: nA and for n: nD

1) calculate the total charge in the region -dp<x<dn and find the relation betweeen dp and dn.

2) Assume you know dn and express the electric field E(x) in therms of dn and the other parameters in -dp<x<dn

2. Relevant equations

Gauss Law for Dielectrics.

D = εE (Assuming Linear homogeneous material)

3. The attempt at a solution

1) I've integrated over the entire volume and found: [itex]Q_{tot} = -Ad_pn_A+Ad_nn_D=d_nn_D-d_pn_A[/itex]

2) I read from the assingment, that the free charge is 0 in the region -dp<x<dn, and therefore : [itex] \oint\limits_S\vec{d}\cdot d \vec{a} = 0, \oint\limits_S\epsilon \vec{E} d\vec{a}[/itex] = 0

Is there some misunderstanding? And please forgive my bad language.

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# Electric field inside semiconductor diode

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