Extrinsic Semiconductor An extrinsic semiconductor is a material in which the charge carriers (electrons and holes) are introduced and controlled externa...
An extrinsic semiconductor is a material in which the charge carriers (electrons and holes) are introduced and controlled externally by the user. This means that the intrinsic properties of the material itself are not affected by the presence of the charge carriers.
An extrinsic semiconductor can be created by introducing impurities into a pure semiconductor material. These impurities can be atoms of the same type as the original semiconductor atoms or atoms of a different type.
Examples of extrinsic semiconductors:
P-type semiconductor: P-type semiconductors are created by introducing phosphorus atoms into a pure silicon or germanium lattice. This creates additional holes, which can then be controlled by the user.
N-type semiconductor: N-type semiconductors are created by introducing nitrogen atoms into a pure silicon or germanium lattice. This creates additional electrons, which can then be controlled by the user.
GaAs (Gallium Arsenide): GaAs is a highly n-type semiconductor that is often used in electronic devices.
Extrinsic semiconductors have several advantages over intrinsic semiconductors, including:
Controllable conductivity: The conductivity of an extrinsic semiconductor can be easily controlled by varying the concentration of impurities.
Large bandgap: The bandgap of an extrinsic semiconductor is typically larger than that of an intrinsic semiconductor, which allows for the creation of more energy levels.
High mobility: The mobility of charge carriers in an extrinsic semiconductor is typically higher than that in an intrinsic semiconductor, which allows for faster switching times.
Extrinsic semiconductors are used in a wide variety of electronic devices, including transistors, solar cells, LEDs, and capacitors. They are essential components for the development of modern electronics and communication technologies