Answer Happy

An n-type silicon sample has a resistivity of 0.5 cm at T = 300 K. Assume that the electron mobility un at this temperature is 1250 cm²/V-s, the intrinsic carrier concentration n; for Si at 300 K is 1.0×10¹0 /cm³, and kT=0.026 eV where k is the Boltzmann's constant. (a) What is the donor impurity concentration (assuming that all the donors are ionized and there is no acceptor impurity)? What is the minority carrier concentration? (b) Where is the Fermi level EF relative to intrinsic Fermi level E;? Sketch the band diagram with clear labels of Ec, Ev, Ei, and EF. (c) In order to change the n-type silicon sample into p-type so that the Fermi level EF is 0.36 eV below the intrinsic Fermi level at T = 300 K, what is the concentration of acceptor impurities to be added into the silicon sample?