What happens when carriers move outward, allowing the barrier voltage to increase in reverse bias?

When carriers move outward in a semiconductor device under reverse bias, the result is an increase in the depletion region. In reverse bias conditions, the external voltage applied to the device causes the majority carriers (electrons in n-type material, holes in p-type material) to be pulled away from the junction. This movement leaves behind charged ions in the depletion region, effectively widening that region as the number of free charge carriers diminishes at the junction.

As carriers move away from the junction, the barrier potential increases. The depletion region expands because the fixed charged ions (which create the electric field necessary to maintain the junction) are not compensated by the mobile charge carriers. This increase in the depletion region is significant because it also correlates with the increased barrier height, which makes it more difficult for charge carriers to traverse the junction, reinforcing the reverse-biased state of the diode or semiconductor device.

In contrast, a decrease in the depletion region would imply that more carriers are being injected into the region, which does not happen in reverse bias. Similarly, stabilization of carrier density would suggest a balance that is not typical in reverse bias conditions, where carriers are removed rather than maintained. Fluctuation of barrier voltage does not reflect the consistent increase that occurs as reverse bias intens