Why does the depletion layer increase in reverse biasing?
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Solution
Reverse bias
Reverse bias is when the p-side of the diode is connected to the negative voltage of the battery and the n-side is connected to the positive voltage of the battery.
Explanation
When a diode is reverse-biased, the voltage at the cathode is comparatively higher than the voltage at the anode.
Therefore, there will be no current flow until the diode breaks down.
Since, the p-side of the diode is now connected to the negative terminal of the power supply, the holes in the p-side are pulled away from the junction, leaving behind charged ions causing an increase in width of the depletion region.
This causes an increase in the thickness of the depletion layer.
This allows very less current to flow through the PN junction.
When the diode is reverse biased the majority of charge carriers are pushed away from the junction and more ions are left at the junction thus causing the widening of the depletion region.
