ENEE 313, Spr. ’09 Quiz V - Mar 10, 2009Name:1. Indicate whether the following materials, doped with the indicated acceptor and donor concentrations(NAand ND, respectively) are n-type or p-type. For each case, give the equilibrium electron andhole concentrations n0and p0. Use ni=1×10101/cm3as the intrinsic carrier concentration, and theLaw of Mass Action (n0p0= n2i) as required.(a) (2 pts.) NA= 4 × 10181/cm3, no donors (ND= 0).(b) (2 pts.) NA= 10161/cm3, ND= 5.1 × 10171/cm3.(c) (2 pts.) NA= 10161/cm3, ND= 8 × 10151/cm3.(d) (2 pts.) No acceptors (NA= 0), ND= 5 × 10161/cm3.(Turn over for the next question).12. Use the material in the last case (item d) in Question 1.(a) (5 pts.) Calculate the conductivities due to electrons and holes (σn= qn0µnand σp= qp0µp),using µn= 1500 cm2/V.s and µp= 500 cm2/V.s. q = 1.6 × 10−19C.(b) (2 pts.) Compare the electron conductivity to the hole conductivity.(c) (3 pts.) Qualitatively describe why electron mobility may be higher than hole mobility in thesame
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