Question

Germanium to which 1024 m-3 Ga atoms have been added is an extrinsic semiconductor at room temperature, and virtually all the Ga atoms may be thought of as being ionized (i.e., one charge carrier exists for each Ga atom). Calculate the electrical conductivity of this material in (Ω·m)-1 , assuming electron and hole mobilities of 0.26 and 0.020 m2 /(V·s), respectively

Answer 1

Electrical Conductivity is 3200
`(\Omega m)^(-1)`

Solution:

As per the question:

`N_(A) = 10^(24)\ m^(- 3)\ Ga\ atoms`

Mobility of electrons,
`\mu_(e) = 0.26\ m^(2)/ Vs`

Mobility of holes,
`\mu_(h) = 0.020\ m^(2)/ Vs`

Charge, Q =
`1.6* 10^(- 19)\ C`

Now,

The formula for the conductivity is given by:

`\sigma = N_(A)Q\mu_(h)`

`\sigma = 10^(24)* 1.6* 10^(- 19)* 0.020} = 3200(\Omega m)^(-1)`