kT = 26*10^-3; //in eV
T = 300;
q = 1.6*10^-19;
Na = 10^16;
ni = 1.5*10^10;
eps0 = 8.84*10^-14; //in F/m
eps = 11.9*eps0;
phiF = kT*log(Na/ni);
disp(phiF,"the potential φF (in V) = ")
W = (4*eps*phiF/(q*Na))^0.5;
disp(W,"The corresponding space charge width(in cm) = ")