Reverse current or Reverse leakage current

In My community page on Facebook one of the member posted a question asking me to explain the reverse current.

Well i thought of writing a post in a not technical way. so that they can relate it to real life scenario.

Semi-conductor devices are made of either a p-type material or an n-type material (semi conductor metal) which always forms a junction. The point where both the metal are fused to atomic level.
(gluing items like sticking duct tape is at surface level)

Biasing a semi-conductor device means applying external electric source(battery). Diode is the simplest form of a semi conductor device. from Wikipedia

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 at higher electric potential than the n-side), this depletion region is diminished, allowing for significant conduction, while only very small current can be achieved when the diode is reverse biased and thus the depletion region expanded.

 as it says when you reverse biase, a small current still flows that varied based on the dopent concentration. Can read wikipedia for more detail (search for semiconductor devices)

Reverse current is of the order on micro-amps. It can be found in the device datasheets. Ideally reverse current should be zero but world is never perfect. Hence we have to live with it. So you have to take care of this reverse current by applying different technique.

In Micro-controllers reverse current could trigger unwanted actions, hence you need to take necessary precautions to counter this.