NEETPhysicsSemiconductors
Statement I : When a Si sample is doped with Boron, it becomes P type and when doped by Arsenic it becomes N-type semi conductor such that P-type has excess holes and N-type has excess electrons. Statement II : When such P-type and N-type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ammeter. In the light of above statements, choose
Options
- ABoth Statement I and statement II are incorrect
- BStatement I is incorrect but statement II is correct
- CBoth Statement I and statement II are correct
- DStatement I is correct but statement II is incorrect
Correct answer
D. Statement I is correct but statement II is incorrect
Step-by-step solution
Doping silicon with boron leads to holes without any additional electron. This results in P-type semiconductors. Arsenic is pentavalent therefore when added with silicon it leaves one electron as a free electron. This results in N-type semiconductors. When such P-type and N-type semiconductors are fused to make a junction, an electric field is produced from the N-side to the P-side, causing a barrier potential to develop. Because of the barrier potential, the majority of charge carriers are unable to flow through t