How does reverse bias limit current through a p-n junction?

When a p-n junction is reverse-biased—meaning a positive voltage is applied to the n-side relative to the p-side—the majority charge carriers are pulled away from the junction.123

In this state, the depletion layer, which acts as an insulator, effectively prevents the majority carriers from crossing the barrier. Because the majority carriers move in opposite directions away from the junction, they cannot sustain a significant flow of electricity. Consequently, only a very small leakage current flows through the device. This current remains minimal until the applied voltage reaches a critical level known as the breakdown voltage, at which point the junction undergoes a sudden increase in current.123