Find the extrinsic conductivity of germanium doped with indium to a concentration of `2xx10^(22)m^(-3)`, with antimony to a concentration of `5xx10^(21)m^(-3)`.

Answer

`5.8xx10^(2)*ohm^(-1)*m^(-1);3.0xx10^(2)ohm^(-1)*m^(-1)`.

Explanation

Since indium is a trivalent element, the indium impurity acts as an acceptor and produces hole-type conductivity. Knowing the concentration of holes and their mobility, we obtain `gamma=en_(+)b_(+)`. Antimony is a pentavalent element, so the antimony impurity acts as a donor. The electric conductivity is `gamma=en_(-)b_(-)`.