Semiconductor devices: Why are suitable impurities (dopants) intentionally added to a pure semiconductor? State the primary objective of doping for electronic applications (diodes, transistors, ICs). Choose the correct option.
IIT JEE
Physics
Difficulty: Easy
Choose an option
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ATo strengthen the crystal mechanically
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BTo increase its electrical conductivity by increasing free carriers (form n-type or p-type)
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CTo raise its melting point significantly
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DTo make it an ideal thermal insulator
Answer
Correct Answer: To increase its electrical conductivity by increasing free carriers (form n-type or p-type)
Explanation
ConceptDoping introduces donor (n-type) or acceptor (p-type) atoms, raising electron or hole concentration. This lowers resistivity and enables controllable junction behavior.
ResultDevices rely on engineered carrier profiles (pn junctions, MOSFET channels).
Final AnswerTo increase its electrical conductivity by increasing free carriers (form n-type or p-type)