Lecture16(1)

A for 0 x p x xx 0 qn d for 0 x n qn d for xn 0 x xn

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Unformatted text preview: 0 0 qN A for p p qN A for 0 x p x xx 0 qN D for 0 x n qN D for xn 0 x xn D 0 0 qNforx xfor x x and x x x n for p xn p and 0 for x x p and x x n thus, , thus thus, qN A qN A for x p for x p x x 0 0 qN A KK o for x S x0 p So KqNoD dE S qN dE for qN D D for 0 0 x x x n n dE dx KK o for 0 x x x S dx n So dx 0 0Kforo x x x x and x x x n S for p xn p and 0 for x x p and x x n Fig. 5.9 a a and b Fig. 5.9 and b Fig. 5.9 a and b Where we have used: Where we have used: dE Ks: Dielectric Constant Where dx dE K used: we have Ks: Dielectric Constant dE dx K Georgia Tech S Georgia Tech Georgia Tech dx KS o S o o EE ECE 3080 - Dr. Alan Dooli ECE 3080 - Dr. Alan Do ECE 3080 - Dr. Alan 332 Spring 2013 Dooli Movement of electrons and holes when forming the junction Electric Field in Depletiontep Junction Solution Region Depletion Region Approximation: S E ( x) 0 x dE ' xp qN A dx' KS o qN A x KS o E ( x) xp for for xp xp x x 0 0 and 0 E ( x) dE ' E ( x) xn x qN D dx' KS o qN D xn KS o x for 0 x xn for 0 x xn Since E(x=0-)=E(x=0+) NAxp=NDxn Georgia Tech ECE 3080 - Dr. Alan Doolittle EE 332 Spring 2013 Depletion Region Approximation: Step Junction Solution M dV E ovement of electrons and holes when forming the junction dx Depletion Region Approximation: Step Junction Solution dV V=VBi E qN A dx x p x for x p x 0 dV KS o V=VBi dxqN A qN D x x for 0 x x n n xp K S o x for x p x 0 dV KS o V=0 dx or , qN D x x for 0 x x n n ) V ( xK S o x qN A dV ' x p x' dx' for x p x 0 V=0 xp K or , 0 So V ( x) x qNnA qN D VBi x dV ' dV ' x p xx' dx'' dx'forforx0p xx x0 x n n 0 xp K x V ( x) K SoSo VBi xn qN D qN A x x' dx' for 0 x x 2 dV ' n n xp x for x p x 0 V ( x) xK 2SK So o V ( x) qN A qN 2 2 x p Dx x n for x for 0 x0 x n x Vbi x p 2K S 2K S...
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This document was uploaded on 02/18/2014.

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