(a) The room-temperature electrical conductivity of a silicon specimen is 5.93 x 10???3 (?-m)???1. The hole concentration is known to be 7.0 x 1017 m???3. Using the electron and hole mobilities for silicon in Table 18.3, compute the electron concentration.

(b) On the basis of the result in part (a), is the specimen intrinsic, n-type extrinsic, or p-type extrinsic? Why?

Electrical Band Gap (eV) Conductivity [(2-m)- Hole Mobility (m/V-s) Electron Mobility (m/V-s) Material Elemental 4 x 10-4 Si 0.14 0.05 1.11 0.67 2.2 0.38 0.18 Ge III-V Compounds 0.015 0.04 GaP GaAs 2.25 1.42 0.17 0.03 0.85 10-6 2 x 104 InSb 7.7 0.07 II-VI Compounds Cds 2.40 0.03 ZnTe 2.26 0.03 0.01