Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / secs1d-0.0.8 / DDG / DDGelectron_driftdiffusion.m

diff --git a/octave_packages/secs1d-0.0.8/DDG/DDGelectron_driftdiffusion.m b/octave_packages/secs1d-0.0.8/DDG/DDGelectron_driftdiffusion.m
new file mode 100644 (file)
index 0000000..62da823
--- /dev/null
+++ b/octave_packages/secs1d-0.0.8/DDG/DDGelectron_driftdiffusion.m
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+function n=DDGelectron_driftdiffusion(psi,x,ng,p,ni,tn,tp,un)
+  
+% n=DDGelectron_driftdiffusion(psi,x,ng,p)
+%     Solves the continuity equation for electrons
+%     input:  psi   electric potential
+%              x     integration domain
+%             ng    initial guess and BCs for electron density
+%             p     hole density (for SRH recombination)
+%     output: n     updated electron density
+  
+## This file is part of 
+##
+## SECS1D - A 1-D Drift--Diffusion Semiconductor Device Simulator
+## -------------------------------------------------------------------
+## Copyright (C) 2004-2007  Carlo de Falco
+##
+##
+##
+##  SECS1D is free software; you can redistribute it and/or modify
+##  it under the terms of the GNU General Public License as published by
+##  the Free Software Foundation; either version 2 of the License, or
+##  (at your option) any later version.
+##
+##  SECS1D is distributed in the hope that it will be useful,
+##  but WITHOUT ANY WARRANTY; without even the implied warranty of
+##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+##  GNU General Public License for more details.
+##
+##  You should have received a copy of the GNU General Public License
+##  along with SECS1D; If not, see <http://www.gnu.org/licenses/>.
+
+
+nodes        = x;
+Nnodes     =length(nodes);
+
+elements   = [[1:Nnodes-1]' [2:Nnodes]'];
+Nelements=size(elements,1);
+
+Bcnodes = [1;Nnodes];
+
+nl = ng(1);
+nr = ng(Nnodes);
+
+h=nodes(elements(:,2))-nodes(elements(:,1));
+
+c=1./h;
+Bneg=Ubernoulli(-(psi(2:Nnodes)-psi(1:Nnodes-1)),1);
+Bpos=Ubernoulli( (psi(2:Nnodes)-psi(1:Nnodes-1)),1);
+
+
+d0    = [c(1).*Bneg(1); c(1:end-1).*Bpos(1:end-1)+c(2:end).*Bneg(2:end); c(end)*Bpos(end)];
+d1    = [1000;-c.* Bpos];
+dm1   = [-c.* Bneg;1000];
+
+A = spdiags([dm1 d0 d1],-1:1,Nnodes,Nnodes);
+b = zeros(Nnodes,1);%- A * ng;
+
+% SRH Recombination term
+SRHD = tp * (ng + ni) + tn * (p + ni);
+SRHL = p ./ SRHD;
+SRHR = ni.^2 ./ SRHD;
+
+ASRH = Ucompmass (nodes,Nnodes,elements,Nelements,SRHL,ones(Nelements,1));
+bSRH = Ucompconst (nodes,Nnodes,elements,Nelements,SRHR,ones(Nelements,1));
+
+A = A + ASRH;
+b = b + bSRH;
+
+% Boundary conditions
+b(Bcnodes)   = [];
+b(1)         = - A(2,1) * nl;
+b(end)       = - A(end-1,end) * nr;
+A(Bcnodes,:) = [];
+A(:,Bcnodes) = [];
+
+n = [nl; A\b ;nr];
+
+
+% Last Revision:
+% $Author: adb014 $
+% $Date: 2008-02-04 16:26:27 +0100 (man, 04 feb 2008) $
+