Q145 / 180 · COMEDK 2024 (Afternoon Shift) · Physics
In intrinsic semiconductors at room temperature, number of electrons and holes are
- Azero
- Bunequal
- Correct answerCequal
- Dinfinity
Solution
In an intrinsic semiconductor, the charge carriers are generated solely due to thermal excitation of electrons from the valence band to the conduction band.
When an electron is excited to the conduction band, it leaves behind a vacancy in the valence band, which is referred to as a hole.
Since each thermal excitation produces exactly one electron in the conduction band and one hole in the valence band, the number density of electrons $n_e$ is equal to the number density of holes $n_h$.
Therefore, $n_e = n_h = n_i$, where $n_i$ is the intrinsic carrier concentration.
Answer: equal
When an electron is excited to the conduction band, it leaves behind a vacancy in the valence band, which is referred to as a hole.
Since each thermal excitation produces exactly one electron in the conduction band and one hole in the valence band, the number density of electrons $n_e$ is equal to the number density of holes $n_h$.
Therefore, $n_e = n_h = n_i$, where $n_i$ is the intrinsic carrier concentration.
Answer: equal
Hence, the correct answer is option: 'C'.