Löcherströme

Löcherströme, also known as hole currents, are a fundamental concept in semiconductor physics. They represent the movement of charge carriers in semiconductor materials, specifically the apparent flow of positive charge. In intrinsic semiconductors, both electrons and holes contribute to electrical conductivity. While electrons are negatively charged particles, holes are considered quasiparticles that behave as if they are positively charged.

A hole can be visualized as the absence of an electron in the valence band of a semiconductor. When an electron moves from one location to another, it leaves behind a vacant state, which is a hole. This vacant state can then be filled by an electron from an adjacent bond, effectively causing the hole to move in the opposite direction of the electron's movement. This apparent movement of positive charge constitutes the hole current.

The concept of holes is crucial for understanding the behavior of p-type semiconductors, where the majority charge carriers are indeed holes. In these materials, doping with trivalent atoms introduces an excess of holes in the valence band, leading to a higher conductivity for positive charge carriers. The mobility of holes is generally lower than that of electrons due to their more complex nature and interaction with the crystal lattice. Löcherströme are essential for the operation of various electronic devices, including diodes, transistors, and integrated circuits, enabling the control and manipulation of electrical signals.