How does the resistance of an intrinsic semiconductor change as its temperature increases?
Answer and explanation
Correct answer: C. It decreases exponentially
- Step 1: In semiconductors, valence electrons are excited across the bandgap into the conduction band by heat. Step 2. Carrier concentration n increases exponentially with temperature: n proportional to e^(-E_g / (2k_BT)). Answer: It decreases exponentially. Why not the others: Metals have positive temperature coefficient (resistance rises); semiconductors have negative (resistance falls).
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