me = 9.109*10^-31; mh = 0.34*me; me2 = 0.32*me; 
    k = 1.38*10^-23; T = 295; a = 5.43*10^-10; em = 1.602*10^-19; 
    Eg = 1.1*em; Ed = 45*10^-3*em; ED = Eg - Ed; h = 6.626*10^-34; 
    NC = 2*(2*π*me2*k*T/(h^2))^(3/2); 
    NV = 2*(2*π*mh*k*T/(h^2))^(3/2);

μ = 1/2*Eg + 3/4*k*T*Log[mh/me2]

ND = 8*10^-5/a^3

4.9967831022686546`*^23

ND0 = ND/(Exp[(Ed - μ)/k/T] + 1)

4.996783091089188`*^23

nd = ND - ND0

ni = Sqrt[NC*ND]*Exp[-Eg/2/k/T]

nd/ni

nd2 = 2*ND*1/(1 + Sqrt[1 + 4*ND/NC*Exp[Ed/k/T]])

nd2/ni