i need help to solve this problem%% Counters and Constantsk=0;m=0;Ht=4E-13;%% Input ParametersN=19;D1=-2.0;IA=50;VS=zeros(1,19);U=zeros(1,19);H=2.5E-5;eps=9.47E-13;q=1.602E-19;pi=3.1415;T=300;k=1.38E-23;Vt=(k*T)/q;%% Boundary ConditionsU1(1)=0.5;U10=0.5;U1(19)=2.5;%% Initial Electron DensityAn1(1) = 6E14;An(19) = 6E14;An1(19) = 6E14;And = 6E14;for i = 1:19; An(i)=2E15;end%% Elements of Matrix AA=zeros(18,18);for i=1:18; j=i; A(i,j)=-2;endfor i=1:18; j=i+1; A(i,j)=1; A(j,i)=1;endAinv=inv(A);for k=1:145%% Elements of Matrix Cfor j=1:19; C(j)=((An(j)-And)/eps)*H*H*q;endC(1)=C(1)-0.5;C(19)=C(19)-2.5;for i=1:19 U1(i)=U1(i)+Ainv(i,j)*C(j);end%% Electric FieldE10=-(3.0*U10+4*U1(1)-U1(2))/(2*H);E1(1)=-(U1(2)-0.5)/(2*H);for j=2:18; E1(j)=-(U1(j+1)-U1(j-1))/(2*H);endE1(19)=-(3*U1(19)-4*U1(18)+U1(17))/(2*H);C1=sqrt(q/(4*pi*eps));C2=q*C1;D=abs(E10);%% Depletion WidthVb1=1;Vab=1.5;Vb=abs(Vb1+Vab);W=sqrt((2*eps*Vb)/(q*And));Deltab=C1*sqrt(D);%% Input VelocityE0=4E+3;S0=8000;Vsa=0.85E+7;Vn0=(S0*abs(E10)+Vsa*(E10/E0)^4)/(1+(E10/E0)^4);for i=1:19; Vn(i)=(S0*abs(E1(i))+Vsa*(E1(i)/E0)^4)/(1+(E1(i)/E0)^4);end%% MobilitySc0=Vn0/abs(E10);for i=1:19; S(i)=Vn(i)/abs(E1(i));end%% Total Velocity (Drift + Diffusion)Vn10=Vn0-0.5*Sc0*Vt*((11*An(1)+18*An(1)-9*An(2)+2*An(3))/(61*An(1)*H));Vn1(1)=Vn(1)-0.5*S(1)*Vt*((An(2)-And)/(H*An(1)));for j=2:18 Vn1(j)=Vn(j)-S(j)*Vt*((An(j+1)-An(j-1))/(2*An(j)*H));endVn1(19)=Vn(19)-S(19)+Vt*(3*An(19)-4*An(18)+An(17))/(2*An(19)*Vt*H);%% Currnt Density TestDif=(fjmax(C2,D)-An(1)*Vn10)*(Ht/H);%% update Electron densityAn10=An(1)+(fjmax(C,D)-An(1)*Vn10)*(Ht/H);% An1(1)=An(1)+(fjmax(C,D)-An(1)*Vn1(1))*(Ht/H);for i=2:19; An1(i)=An(i)-(An(i)*Vn1(i)-An(i-1)*Vn1(i-1))*(Ht/H);end%% Displacement CurrentDisp(1)=((U1(2)-U10)-(U(2)-U1(1)))*(1/(H*Ht))*(eps/q);for i=2:18 Disp(i)=((U1(i+1)-U1(i-1))-(U(i+1)-U(i-1)))*(1/(H*Ht))*(eps/q);endDisp(19)=Disp(18);%% PARTICAL CURRENTVs=zeros(50);for i=1:19 Anvn(i)=0.5*(An1(i)+An(i))*(Vn1(i)+Vs(i));end%% TOTAL CURRENTfor i=1:18 Ajt(i)=-0.5*Anvn(i)+0.5*Disp(i);endAjt(19)=Ajt(18);for I=1:19 Ajc(i)=-q*An1(i)*Vn1(i);endAjc(19)=Ajc(18);An0=An10;for i=1:19; An(i)=An1(i)endfor i=1:N Vs(i)=Vn1(i)endVs(19)=Vn1(19);for i=1:N U(i)=U1(i)endU(19)=U1(19);end