railway RRB JE (CBT I + CBT II) Mock Test 2024 Electronic Devices Carriers in Semiconductors The Intrinsic and Extrinsic Carrier Concentration
1 cm3 of pure Germanium at 20°C contains about 4.2 × 1022 atoms, 2.5 × 1013 free electrons, and 2.5 × 1013 holes. 0.001% of Arsenic doping donates an extra 1017 free electrons in the same volume. The approximate number of holes in one cm3 in the doped semiconductor under equilibrium condition is:
1
6.25 × 109
2
2.5 × 109
3
10.5 × 109
4
1017