Why does a PN-junction diode not conduct current when reverse biased?
Only P-type semiconductor material can conduct current
Only N-type semiconductor material can conduct current
Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region✓پاسخ درست
Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
توضیح
Reverse bias pulls holes in the P material toward the negative terminal and electrons in the N material toward the positive one, so carriers retreat from the junction and the carrier-free depletion region widens; with nothing left to carry charge across it, only a small leakage current flows. Both P-type and N-type material conduct perfectly well on their own, and nothing is permanently converted into an insulator.