Concept:When a neutral trivalent acceptor atom (e.g., Boron) captures an electron from an adjacent covalent bond to create a hole, it acquires a net negative charge and remains fixed in the lattice.
Formula:$$\text{Acceptor Ionization: } N_A^0 + e^- \longrightarrow N_A^- \quad (\text{creating a hole } h^+)$$
Solution:- The created hole acts as a mobile positive charge carrier in the valence band.
- The acceptor atom itself becomes a negatively charged ion (\( N_A^- \)) locked in the lattice.
- Thus, the immobile charges in P-type material are negative acceptor ions.
Why other options are incorrect:- Option A: Positive donor ions are found in N-type semiconductors.
- Option C: Conduction electrons are mobile carriers.
- Option D: Valence holes are mobile carriers, not fixed ions.
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