Question Detail
Question
Which of the following is true about intrinsic semiconductor?
i. Each semiconductor atom undergo paired sharing of electrons with four neighbouring atoms.
ii. Conduction is due equally to holes and electrons.
iii. Group V atoms in the semiconductor share four electrons with four neighbouring atoms with an extra electron.
iv. Band structure is between that of metals and insulators.
i. Each semiconductor atom undergo paired sharing of electrons with four neighbouring atoms.
ii. Conduction is due equally to holes and electrons.
iii. Group V atoms in the semiconductor share four electrons with four neighbouring atoms with an extra electron.
iv. Band structure is between that of metals and insulators.
Correct Answer
Option B is the correct answer.
Detailed Explanation
Statement i is true because intrinsic semiconductors (like silicon or germanium) form covalent bonds, with each atom sharing four valence electrons with its four neighbors. Statement ii is true as, in an intrinsic semiconductor, electron-hole pairs are generated in equal numbers, leading to equal contributions from electrons and holes to conduction. Statement iii is false because Group V atoms are donor impurities used in extrinsic n-type semiconductors, not intrinsic ones. Statement iv is true because semiconductors have an energy band gap larger than conductors (metals) but smaller than insulators.
Hint
Distinguish between intrinsic and extrinsic semiconductors and recall their fundamental properties regarding bonding, charge carriers, and energy bands.