How does current flow in a depletion region?

Answer 1

Dear Sarah,
A depletion layer has no free carriers (holes or electrons). If there are a few residual thermal or radiation induced ones then these will carry current. We use this effect to detect light or radiation!

Otherwise the depletion layer forms a capacitor between two conductors. The flow is then by displacement current as seen in Maxwell's Laws. These means that in MOSFET machines, such as a portable computer, the current flowing depends on the ClockRate of the CPU and Memory and some have the facility to reduce the clockrate to conserve the battery.

I hope this is of help to you.
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