Semiconductor Ceramics are a class of functional ceramic materials with unique electrical properties. Their conductivity lies between that of conductors and insulators and can be adjusted through compositional control, doping, or processing methods to exhibit semiconductor characteristics.
Semiconducting Mechanism:
Free charge carriers (electrons or holes) are introduced through doping (e.g., adding elements with different valence states into metal oxides) or defect engineering (such as creating oxygen vacancies).
Nonlinear Conductivity:
For example, varistor ceramics (such as ZnO) show a sudden drop in resistance at a critical voltage, serving as overvoltage protection.
Temperature Sensitivity:
Positive Temperature Coefficient (PTC) ceramics (such as BaTiO₃-based materials) exhibit a sharp increase in resistance with rising temperature, enabling self-regulating heating applications.
