Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Semiconductors and Semiconductor Devices
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Semiconductors and Semiconductor Devices
Suppose n_p and n_e denote the numbers of holes and conduction...
Suppose and denote the numbers of holes and conduction electrons in an extrinsic semiconductor.
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
In an intrinsic semiconductor, the number of holes is equal to the number of conduction electrons, giving .
An extrinsic semiconductor is formed by doping an intrinsic semiconductor with either pentavalent or trivalent impurities.
For an n-type semiconductor, electrons are the majority charge carriers, so .
For a p-type semiconductor, holes are the majority charge carriers, so .
Therefore, in any extrinsic semiconductor, the number of holes is never equal to the number of conduction electrons, which implies .
An extrinsic semiconductor is formed by doping an intrinsic semiconductor with either pentavalent or trivalent impurities.
For an n-type semiconductor, electrons are the majority charge carriers, so .
For a p-type semiconductor, holes are the majority charge carriers, so .
Therefore, in any extrinsic semiconductor, the number of holes is never equal to the number of conduction electrons, which implies .