Concept:Connecting both terminals to ground sets the external potential difference across the diode to zero (\(V_{\text{applied}} = 0\text{ V}\)). In thermal equilibrium with zero external bias, the forward diffusion current of majority carriers is balanced by the reverse drift current of minority carriers, yielding zero net current.
Formula:$$I_{\text{net}} = I_{\text{diffusion}} - I_{\text{drift}} = 0$$
Solution:- Zero applied potential difference means the built-in barrier potential remains intact.
- No external energy source is present to drive charge carriers around the loop.
- Therefore, the net current through the diode is identically zero.
Why other options are incorrect:- Option A: Net forward conduction requires an applied external forward voltage greater than the barrier potential.
- Option C: Photon emission (as in LEDs) requires energetic forward recombination powered by an external source.
- Option D: Breakdown requires strong reverse over-voltage; zero bias cannot cause breakdown.
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