1. Conductors, semiconductors, and insulators

Materials can be divided into three categories according to their ability to conduct an electric current:

  • Conductors: Materials that easily conduct electricity (i.e., materials with high electrical conductivity and low electrical resistivity)
  • Semiconductors: Materials with an electrical conductivity value that falls between that of a conductor and that of an insulator
  • Insulators: Materials that do not readily conduct electricity (i.e., materials with high electrical resistivity)

Conductors have electrical resistivity on the order of 10-8 to 10-4 Ωcm whereas insulators have electrical resistivity on the order of 108 to 1018 Ωcm. Semiconductors have an electrical resistivity value between those of conductors and insulators—10-4 to 108 Ωcm.

Electrical resistivity: Ωcm

Figure 1-1 Categories of materials according to their electrical resistivity
Figure 1-1 Categories of materials according to their electrical resistivity
Figure 1-2 Definition of the electrical resistance of a material
Figure 1-2 Definition of the electrical resistance of a material

Electrical resistance (R) is the resistance to a flow of electric current through a material. The electrical resistance of a material is proportional to its length (l) and inversely proportional to its cross-sectional area (A). Each material has also an intrinsic property called electrical resistivity (ρ). Electrical resistance (R) is expressed as follows as a function of ρ, I and A. Electrical resistivity (ρ) is determined by the energy level (band) of the electrons in the outermost shell of an atom, crystalline states, and other factors.

Chapter1 Basics of Schottky Barrier Diodes (Basic of Semiconductor Device)

1-1. Energy band diagram
Details
1-2. Characteristics of an intrinsic silicon semiconductor
Details
1-3. pn junction
Details
1-3-1. Forward biasing
Details
1-3-2. Reverse biasing
Details

Related information

Back to Basics of Schottky Barrier Diodes

A new window will open