A pure Si crystal has 6 × 1028 atoms m-3. It is doped by 1 ppm concentration of pentavalent As. Then the number of electrons and holes are:
(Given that ni = 1.5 × 1016 m-3)
1
6 × 1028 m-3 and 3.75 × 109 m-3
2
6 × 1025 m-3 and 3.75 × 1019 m-3
3
6 × 1022 m-3 and 3.75 × 109 m-3
4
6 × 1022 m-3 and 3.75 × 1019 m-3