Statement-I: By doping silicon semiconductor with pentavalent material, the electrons density increases.
Statement-II: The n-type semiconductor has net negative charge.
In the light of the above statements, choose the most appropriate answer from the options given below:
Statement-II: The n-type semiconductor has net negative charge.
In the light of the above statements, choose the most appropriate answer from the options given below:
- (A)Both Statement-I and Statement-II are true.
- (B)Statement-I is true but Statement-II is false.✓ Correct
- (C)Statement-I is false but Statement-II is true.
- (D)Both Statement-I and Statement-II are false.
Answer: (B)
Solution
A pentavalent dopant supplies one electron more than the four needed for the covalent bonds, and that electron is free at room temperature, so the free-electron density rises far above the intrinsic value. Each donor that releases an electron is left behind as a fixed positive ion in the lattice, so the extra electrons are exactly balanced by the donor ions and the crystal stays electrically neutral. Statement I is true and Statement II is false.
JEE Main · 2021 · 26 Aug 2021 · Shift 1 · Single correct option