1. Germanium to which 1024 m-3 As atoms have been added is an extrinsic semiconductor at room temperature, and virtually all the As atoms may be thought of as being ionized (i.e., one charge carrier exists for each As atom).
(a) Is this material n-type or p-type?
(b) Calculate the electrical conductivity of this material, assuming electron and hole mo- bilities of 0.1 and 0.05 m2/V-s, respectively.
2. The following electrical characteristics have been determined for both intrinsic and p-type extrinsic gallium antimonide (GaSb) at room temperature:
An electron concentration of 5 x 1017 m-3. If the electron drift velocity is 350 m/s in an electric field of 1000 V/m, calculate the con- ductivity of this material.