Question

In an unbiased p-n junction, at equilibrium, which of the following statements is true ?

• A. Diffusion current is zero but drift current exists.
• B. Diffusion current exists but drift current is zero.
• C. Diffusion and drift currents are equal and opposite.
• D. Both the diffusion and drift currents exist but are unequal.

Hint:

For an unbiased p-n junction at equilibrium, \[ I_{\text{diffusion}} = I_{\text{drift}} \] in magnitude, but they flow in opposite directions. Therefore, \[ I_{\text{net}}=0. \] Remember: \[ \boxed{\text{Equilibrium } \Rightarrow \text{ Net current } = 0} \] because diffusion current is exactly balanced by drift current.

Answer 1

The Correct Option is C