The number of silicon atoms per `m^(3) is 5xx10^(28)`. This is doped simultaneously with `5xx10^(22)` atoms per `m^(3)` of Arsenic and `5xx10^(20) per m^(3)` atoms of indium. Calculate the number of electrons and holes. Given that `n_(i)=1.5xx10^(16)m^(-3)`. Is the material n-type or p-type?

Explanation

`n_(c) = 4.95 xx 10^(22), n_(h) = 4.75 xx 10^(9)`, n-type since `n_(e) gt gt n_(h)`
For charge neutrality `N_(D)-N_(A) = n_(e).n_(h) = n_(i)^(2)`
Solving these equations, `n_(e) = 1/2 [(N_(D)-N_(A)) + sqrt((N_(D)-N_(A))^(2) + 4n_(i)^(2))]`