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
Let's analyze each statement for an intrinsic semiconductor:i. In intrinsic semiconductors (like pure silicon or germanium), atoms form covalent bonds, sharing four valence electrons with four neighboring atoms. This statement is true.ii. In an intrinsic semiconductor, electron-hole pairs are generated by thermal energy. The number of free electrons in the conduction band is equal to the number of holes in the valence band, meaning conduction is due equally to both. This statement is true.iii. Group V atoms are donor impurities used to create n-type (extrinsic) semiconductors, not intrinsic ones. This statement describes doping for n-type, not intrinsic properties, and is therefore false in the context of intrinsic semiconductors.iv. The band gap of semiconductors is smaller than insulators but larger than metals (which have overlapping bands or no band gap). This statement is true.Thus, statements i, ii, and iv are true.
Hint
Recall the definition and characteristics of an intrinsic semiconductor, including its atomic bonding, charge carriers, and band structure.