Donordefecten

Donordefecten, a term often encountered in semiconductor physics and materials science, refers to imperfections within a crystalline lattice that are introduced by the presence of donor atoms. Donor atoms are elements intentionally added to a semiconductor material, such as silicon or germanium, to increase its concentration of free electrons. These donor atoms typically have more valence electrons than the host semiconductor atoms. For instance, in silicon (Group 14), elements from Group 15 like phosphorus or arsenic are used as donors. When a donor atom substitutes for a host atom in the lattice, it forms covalent bonds with its neighbors. However, one of its valence electrons is only loosely bound and can be easily excited into the conduction band, becoming a free charge carrier.

The presence of these donor atoms creates what are termed "donordefecten" in the sense that they introduce a deviation from the pristine, intrinsic semiconductor structure. These are not necessarily detrimental defects; in fact, they are fundamental to creating n-type semiconductors, which are essential components in electronic devices like transistors and diodes. The concentration of these donordefecten directly dictates the electrical conductivity of the semiconductor. Higher concentrations lead to a higher density of free electrons and thus greater conductivity. Conversely, controlling the precise number and distribution of these donor atoms is crucial for tailoring the electronic properties of semiconductors for specific applications. While often referred to as defects, in the context of doping, they are intentionally introduced imperfections that are vital for semiconductor functionality.