Puolijohteiset

Puolijohteiset are materials that have electrical conductivity between that of a conductor and an insulator. This means their conductivity can be manipulated by external factors such as heat, light, or the application of an electric field. Commonly, these materials are crystalline solids. The unique electrical properties of puolijohteiset arise from their atomic structure, specifically the way electrons are bound within the material. In conductors, electrons are loosely bound and can move freely, while in insulators, electrons are tightly bound and cannot move easily. Puolijohteiset fall in between, with some electrons able to move under certain conditions.

The most well-known puolijohteiset are elements from Group 14 of the periodic table, such as silicon and germanium. These pure elements are called intrinsic puolijohteiset. However, their conductivity can be significantly altered by a process called doping, where small amounts of impurity atoms are added. Doping can create either n-type puolijohteiset, where excess electrons are available for conduction, or p-type puolijohteiset, where "holes" (absence of electrons) act as charge carriers. The combination of n-type and p-type materials forms the basis of crucial electronic components like diodes and transistors, which are fundamental building blocks of modern electronics, including computers, smartphones, and countless other devices.