Semiconductors
- Conductivity in among those of metals and insulators.
- Conductivity can be changed over orders of magnitude through changes in temperature, optical excitation, and impurity content (doping).
- Usually found in column IV and neighboring columns of the periodic table.
- Elemental semiconductors: Si, Ge.
- Compound semiconductors:
Binary:
GaAs, AlAs, GaP, etc. (III-V).
ZnS, ZnTe, CdSe (II- VI).
SiC, SiGe (IV compounds).
1) Ternary: GaAsP
Quaternary: InGaAsP
2) Si extensively used for rectifiers, transistors, and ICs.
3) III-V compounds extensively used in optoelectronic and high-speed applications.