Question

A silicon specimen is made into a `P`-type semiconductor by dopping, on an average, one helium atoms per `5xx10^(7)` silicon atoms. If the number density of atoms in the silicon specimen is `5xx10^(28) at om//m^(3)` then the number of acceptor atoms in silicon per cubic centimeter will be

Answer 1

The doping of one indium atom in silicon semiconductor will produce one acceptor atom in p-type semiconductor. Since one indium atom has been dopped per `5xx10^(7)` silicon atoms, so number density of acceptor atoms in silicon
`=("no. density of Si atoms")/("doping fraction of impurity atoms")`
`= (5xx10^(28))/(5xx10^(7))=10^(21) "atoms"//m^(3)`
`10^(21)xx10^(-6) "atoms"//cm^(3)`
`1xx10^(15) "atoms"//cm^(3)`