puolijohdekiteen

Puolijohdekide refers to a crystalline solid material that has electrical conductivity between that of a conductor and an insulator. This property is crucial in modern electronics. The conductivity of a semiconductor can be manipulated by introducing impurities through a process called doping, which creates either n-type (excess electrons) or p-type (electron holes) semiconductors.

The behavior of electrons within the crystal lattice of a puolijohdekide is described by band theory. In semiconductors, the valence band (where electrons are normally bound) and the conduction band (where electrons can move freely) are separated by a small energy gap. At absolute zero temperature, the valence band is full and the conduction band is empty, making it an insulator. As temperature increases, or when energy is supplied (e.g., light), electrons can gain enough energy to jump to the conduction band, increasing conductivity.

Common examples of puolijohdekide materials include silicon (Si) and germanium (Ge), which are elements from Group 14 of the periodic table. Compound semiconductors, such as gallium arsenide (GaAs) and indium phosphide (InP), are also widely used. These materials form the foundation of transistors, diodes, integrated circuits, and a vast array of electronic devices that power our digital world. Their ability to control and amplify electrical signals makes them indispensable components in nearly all electronic technologies.