1function c=Udriftdiffusion2(mesh,Dsides,guess,M,U,V,Vth,u) 2 3%% 4% c=Udriftdiffusion(mesh,Dsides,guess,M,U,V,Vth,u) 5% solves the drift diffusion equation 6% $ -div ( u ( \nabla (n Vth) - n \nabla V)) + M = U $ 7%% 8 9% This file is part of 10% 11% SECS2D - A 2-D Drift--Diffusion Semiconductor Device Simulator 12% ------------------------------------------------------------------- 13% Copyright (C) 2004-2006 Carlo de Falco 14% 15% 16% 17% SECS2D is free software; you can redistribute it and/or modify 18% it under the terms of the GNU General Public License as published by 19% the Free Software Foundation; either version 2 of the License, or 20% (at your option) any later version. 21% 22% SECS2D is distributed in the hope that it will be useful, 23% but WITHOUT ANY WARRANTY; without even the implied warranty of 24% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 25% GNU General Public License for more details. 26% 27% You should have received a copy of the GNU General Public License 28% along with SECS2D; If not, see <http://www.gnu.org/licenses/>. 29 30global DDG_RHS DDG_MASS %DEBUG_SGM 31 32Nnodes = max(size(mesh.p)); 33Nelements = max(size(mesh.t)); 34 35 36% Set list of nodes with Dirichelet BCs 37Dnodes=Unodesonside(mesh,Dsides); 38 39% Set values of Dirichelet BCs 40Bc = guess(Dnodes); 41 42% Set list of nodes without Dirichelet BCs 43Varnodes = setdiff([1:Nnodes],Dnodes); 44 45% Build LHS matrix and RHS 46A = Uscharfettergummel2(mesh,V,u,Vth); 47if (isempty(DDG_MASS)) 48 DDG_MASS=Ucompmass2(mesh,ones(Nnodes,1),ones(Nelements,1)); 49end 50A = A + DDG_MASS.*spdiag(M,0); 51 52if (isempty(DDG_RHS)) 53 DDG_RHS=Ucompconst(mesh,ones(Nnodes,1),ones(Nelements,1)); 54end 55b = DDG_RHS.*U; 56 57 58 59%%%%%%%%DEBUG%%%%%%%%%%% 60%DEBUG_SGM = A; 61 62%% Apply boundary conditions 63A (Dnodes,:) = 0; 64b (Dnodes) = 0; 65b = b - A (:,Dnodes) * Bc; 66 67A(Dnodes,:)= []; 68A(:,Dnodes)= []; 69 70b(Dnodes) = []; 71 72 73c = guess; 74c(Varnodes) = A \ b; 75 76