Pure `Si` at `500K` has equal number of electron `(n_(e))` and hole `(n_(h))` concentration of `1.5xx10^(16)m^(-3)`. Dopping by indium. Increases `n_(h)` to `4.5xx10^(22) m^(-3)`. The doped semiconductor is of

Options

A. n-type with electron concentration `n_(e)xx5xx10^(22)m^(-3)`
B. p-type with electron concentration `n_(e)xx2.5xx10^(10)m^(-3)`
C. n-type with electron concentration `n_(e)xx2.5xx10^(23)m^(-3)`
D. p-type having electron concentration `n_(e)xx5xx10^(9)m^(-3)`

Answer

D

Explanation

`n_(i)^(2)=n_(e)n_(h)impliesn_(e)=((n_(i))^(2))/(n_(h))`
`n_(e)=(1.5xx10^(16))^(2)/((4.5xx10^(22)))impliesn_(e)=5xx10^(9)m^(-3)`
`:.n_(h)gtgtn_(e)` semiconductor is p-type.