A Ge specimen is doped with Al. The concentration of acceptor atoms is 1021 atoms / m3 . Given that the intrinsic concentration of electron -hole pairs is 1019 / m3 , the concentration of electrons in the specimen is

When Ge specimen is doped with Al, then concentration of acceptor atoms is also called concentration of holes. Using formula, ni2=n0p0wheren1 = concentration of electron hole pair = 1019m-3n0 = concentration of electronp0 = concentration of holes = 1021atom m-3⇒10192=1021×n0⇒n0=1017m−3