Discussion
When an electron is thermally excited to conduction band in semiconductor, an electron is surrounded by :
Answer: C
The electron is surrounded by a large number of unoccupied energy states.
The conduction band of a semiconductor contains a very large number of allowed states, and at ordinary temperatures only a tiny fraction of them hold electrons. An electron excited into the band therefore finds plenty of empty states next to it in energy, which is why it can gain a little energy from an applied field, move into a neighbouring state, and conduct.
The options describing a very small number of states, or a band full of occupied states, describe the valence band of an insulator-like case, where a full band leaves no room for the electron to move.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development