Briefly describe electron and hole motions in a \(p-n\) junction for forward and reverse biases; then explain how these lead to rectification.

Briefly describe the motion of electrons and holes in a p-n junction under forward and reverse biases and explain how this motion leads to rectification. Under forward bias, the applied voltage reduces the potential barrier at the depletion region, causing electrons to move from the n-side to the p-side and holes to move from the p-side to the n-side, resulting in a flow of current across the junction. In reverse bias, the potential barrier increases, making it difficult for electrons and holes to recombine. Electrons and holes are drawn away from the junction, significantly reducing or even blocking current flow. Rectification occurs because the p-n junction allows current to flow more easily in one direction (forward bias) than in the opposite direction (reverse bias), converting an alternating current (AC) signal into a direct current (DC) signal.