NEET2008PhysicsSemiconductorsActual
A Ge specimen is doped with Al. The concentration of acceptor atoms is ( 10²¹ ) atoms (/ m ^3 ). Given that the intrinsic concentration of electron hole pairs is (10¹⁹ / m ^3 ), the concentration of electrons in the specimen is
Options
- A(10¹⁷ / m ^3 )
- B(10¹⁵ / m ^3 )
- C(10^4 / m ^3 )
- D(10^2 / m ^3 ).
Correct answer
A. (10¹⁷ / m ^3 )
Step-by-step solution
n_h=10²¹ atoms / m ^3n_i=10¹⁹ atoms / m ^3, n_e= ? n_e n_h=n_i^2n_e= n_i^2 n_h = (10¹⁹ )^2 10²¹ = 10³⁸ 10²¹ =10¹⁷ atoms / m ^3 .