Editing Semiconductor device (section)

===Diode===
{{Main|Diode}}
A semiconductor diode is a device typically made from a single [[p–n junction]]. At the junction of a p-type and an [[n-type semiconductor]], there forms a [[depletion region]] where current conduction is inhibited by the lack of mobile charge carriers. When the device is ''forward biased'' (connected with the p-side, having a higher [[electric potential]] than the n-side), this depletion region is diminished, allowing for significant conduction. Contrariwise, only a very small current can be achieved when the diode is ''reverse biased'' (connected with the n-side at higher electric potential than the p-side, and thus the depletion region expanded).

Exposing a semiconductor to [[light]] can generate [[electron–hole pair]]s, which increases the number of free carriers and thereby the conductivity. Diodes optimized to take advantage of this phenomenon are known as ''[[photodiode]]s''.
[[Compound semiconductor]] diodes can also produce light, as in [[light-emitting diode]]s and [[laser diode]]