First, ‘x’ and ‘V’ have to have the same numbers of elements (unless you’re defining them as functions, in which case you can use fzero or fsolve to determine the intersection).
With that constraint, this works:
x = linspace(0, 9);
q=1.6022e-19;
C=28.73;
T=273+C
k=1.3806e-23;
Is=1.0e-12;
V= x;
n=1;
Vt=(k*T)/q;
Id=Is*((exp(V/(n*Vt)))-1);
loglog(V,Id)
axis([-1,0.6,-0.1,2])
grid on
title('V-T Characteristics of Diode')
xlabel(' Voltage ')
ylabel(' Current ')
hold on
I = (-1/5000)*x + .0018;
plot(x,I)
xint = interp1(Id-I, x, 0);
yint = (-1/5000)*xint + .0018;
plot(xint, yint, 'pg')
producing:
xint =
0.546332230872042
yint =
0.001690733553826
