With the help of a computer and a commercial software packag

With the help of a computer and a commercial software package such as Matlab to solve the following problems: Write a Matlab program to confirm that the n, versus T curve for greaterthanorequalto and Si graphed in Figure 2.20 can be generated by employing the empirical fit relationships below. Check over the temperature range of 275K lessthanorequalto T lessthanorequalto 375K. n_i(S_i) = (9.15 times 10^19)(T/300)^2 e^-0.5928/kT eqn. 1 n_i(Ge) = (1.76 times 10^16)(T)^3/2 e^-0.392/kT eqn. 2 Generate a MATLAB program to compute and plot the Fermi function, f(E), and 1- f(E) versus Delta E = E-E_f for values of AE that is over the range of -0.5eV lessthanorequalto Delta E lessthanorequalto 0.5eV for varying temperature settings where Temperature 150, 250, 350, 450 and 550K. Make sure that each f(E) versus Delta E curve at each temperature is superimposed on the same plot. Discuss what you see in your plots as the Fermi function. f(E), and l-f(E) varies with temperature and energy. Consider GaAs at T = 300K with N_d =0. Plot the position of the Fermi energy level with respect to the intrinsic Fermi energy level as a function of the acceptor impurity concentration over the range of 10^14 lessthanorequalto Na lessthanorequalto 10^17 cm^-3. Plot the position of the Fermi energy level with respect to the valence-band energy over the same acceptor impurity concentration given in part (a). The temperature of a sample of greaterthanorequalto is T = 300K and the acceptor doping concentration is N_a = 0. Plot the minority carrier concentration (on a log-log plot) versus Nd over the range 10^15 lessthanorequalto Nd lessthanorequalto 10^18 cm^-3

Solution

T=275:375;

k=1.38e-23;

q=1.6e-19;

ni_si=(9.15e19)*(T/300).^2.*exp(-0.5928*q./(k.*T));

ni_ge=(1.76e16).*(T).^(1.5).*exp(-0.392*q./(k.*T));

figure;plot(T,ni_si);hold on

xlabel(\'\\it T (K) \ ightarrow\');

ylabel(\'\\it n_i(Si)(cm^(-3)) \ ightarrow\');

figure;plot(T,ni_ge,\'r\');

xlabel(\'\\it T(K)\ ightarrow\');

ylabel(\'\\it n_i(Ge)(cm^(-3)) \ ightarrow\');