minoritetsbärarlagring

Minoritetsbärarlagring is a term used in semiconductor physics to describe the process of storing charge carriers of the minority type within a semiconductor device. In a semiconductor, the two types of charge carriers are electrons and holes. In an n-type semiconductor, electrons are the majority carriers and holes are the minority carriers, while in a p-type semiconductor, holes are the majority carriers and electrons are the minority carriers.

When an excess of minority carriers is injected into a semiconductor region, for example, through a forward-biased p-n junction, these minority carriers can diffuse into adjacent regions. If these regions are designed to trap or accumulate these minority carriers, it leads to minoritetsbärarlagring. This storage effect is crucial for the operation of certain semiconductor devices, particularly those involving transient behavior or switching.

A key example of minoritetsbärarlagring is observed in bipolar junction transistors (BJTs) and diodes. During switching from a conducting to a non-conducting state, the stored minority carriers in the base region of a BJT or in the depletion region of a diode need to be removed. The time it takes for these carriers to recombine or diffuse away contributes to the switching speed of the device. Devices with significant minoritetsbärarlagring often exhibit a "storage time" or "fall time" that is longer than their turn-on time, impacting their high-frequency performance. Minimizing this storage effect is a design consideration for high-speed switching applications.