/ˌsɛmɪkənˈdʌktər/
noun … “Material with controllable electrical conductivity.”
Semiconductor is a material whose electrical conductivity lies between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (doping), applying voltage, or controlling temperature. Semiconductors are the foundation of modern electronics, enabling the creation of transistors, logic gates, diodes, integrated circuits, microprocessors, and memory devices.
Key characteristics of Semiconductor include:
- Variable conductivity: can act as a conductor or insulator depending on conditions.
- Doping: introducing impurities creates n-type (electron-rich) or p-type (hole-rich) materials.
- Energy band gap: separates valence and conduction bands, controlling electron flow.
- Applications: transistors, diodes, LEDs, solar cells, microcontrollers, and integrated circuits.
- Temperature sensitivity: conductivity changes with temperature and external fields.
Workflow example: Simple p-n junction diode:
-- p-type and n-type semiconductor layers joined
forward_bias = apply_voltage(p_side=positive, n_side=negative)
current = diode.conduct(forward_bias) -- Current flows
reverse_bias = apply_voltage(p_side=negative, n_side=positive)
current = diode.conduct(reverse_bias) -- Minimal current flows
Here, the semiconductor diode conducts current in one direction but blocks it in the other, illustrating controlled conductivity.
Conceptually, a Semiconductor is like a gate that can be opened or closed by external conditions, regulating the flow of electricity.
See Transistor, Logic Gates, Integrated Circuit, Diode, Microcontroller.