A P-type sillicon semiconductor is made by adding one atom of indium per `5xx10^(7)` atoms of sillicon. If the number density of silicon is `25xx10^(28) "atom"//m^(3)`. Point the number of acceptor atoms in per cubic cm. of sillicon

Options

A. `10^15`
B. `1.5xx10^15`
C. `2xx10^15`
D. `2.5xx10^15`

Answer

C

Explanation

No. of Ge atoms/`m^3=8xx10^27`
`therefore` No. of Ge atoms/`cm^3=8xx10^27xx10^(-6)=8xx10^21`
`therefore` No. of Gallium atoms/`cm^3=(8xx10^21)/(4xx10^6)=2xx10^15`