Concept:With rising temperature, the intrinsic carrier concentration \( n_i \) increases exponentially, which reduces the contact potential barrier across the junction.
Formula:$$\frac{d V_0}{d T} \approx -2\text{ mV/}^\circ\text{C} \quad (-0.002\text{ V/K})$$
Solution:- Higher temperature increases thermal excitation, enabling majority carriers to cross the barrier at lower externally applied forward voltages.
- Thus, the potential barrier decreases by approximately \( 2\text{ mV} \) for every \( 1^\circ\text{C} \) rise in temperature.
Why other options are incorrect:- Option A: The barrier potential decreases, not increases, and a change of \( 2\text{ V/}^\circ\text{C} \) is unrealistically large.
- Option B: Barrier potential is temperature-dependent and does not remain constant.
- Option D: The temperature variation is well-defined by semiconductor physics, not unpredictable.
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