请教大牛matlab中fsolve函数的问题

小葡萄

小生编写了以下的matlab程序求解电路问题，由于不熟悉fsolve函数，程序不收敛。初步猜测是fsolve设置不当导致收敛不到我需要的精度，请熟悉fsolve的大牛帮忙看一下程序要怎么改，谢谢

A_final = 0.4; % A_final is the final gain after time t
A0 = 0.5:0.1:0.5; % A0 is the dc gain of a single pre amplifier
fu = 1e10:1e9:1e10;
Tao = 1./(2*pi*fu);
t_init = 1e-11;
z = zeros(size(A0,2),size(Tao,2));
for i = 1:1:size(A0,2)
    for j = 1:1:size(Tao,2)
        f = @(t)exp(t/(A0(i)*Tao(j)))-(1+t/(A0(i)*Tao(j)))/(1-A_final/A0(i));
        options=optimset('DiffMinChange',1e-12,'Display','iter','MaxIter',1e6,'TolFun',1e-12,'TolX',1e-12,'MaxFunEvals',1e6);
        z(i,j) =  fsolve(f,t_init,options);
    end
end