Electrical Properties: Conductors, Semiconductors, and Insulators

Resistivity and Conductivity

• Resistivity and conductivity are inversely related; high resistivity indicates low conductivity and vice versa.
• Conductivity is primarily determined by charge carriers' concentration and mobility.

Conductivity of Electrolytes

• The main factor influencing electrolyte conductivity is the presence and concentration of ions.

Charge Flow

• The flow of electrically charged particles in response to an applied electric field is known as current.

Zero Resistance Material

• Certain materials exhibit zero resistance at specific temperatures, a phenomenon known as superconductivity.

Effect of Deformation on Metals

• Deformation in metals typically results in increased resistivity and reduced conductivity due to dislocation movement.

Voltage and Current Relationship

• The term for voltage divided by current in a material is resistance.

Conductivity of Silver

• The approximate conductivity of silver at room temperature is around 63 x 10^6 Siemens per meter.

Semiconductor Type from Doping

• Adding phosphorus to silicon forms an n-type semiconductor, characterized by excess electrons.

Conductivity at Low Temperatures

• The conductivity of a doped semiconductor decreases significantly at temperatures below 100 K, approaching that of an intrinsic semiconductor.

Effect of Doping on Silicon

• Doping silicon increases its conductivity by introducing additional charge carriers (electrons or holes).

Zinc as an Impurity

• When zinc is added to the compound semiconductor GaAs, it acts as a p-type dopant.

Extrinsic Conductivity Range

• A doped semiconductor exhibits extrinsic conductivity typically in the temperature range of 200 K to 400 K.

Function of p-n Junction Diode

• The primary function of a p-n rectifying junction diode is to allow current to flow in one direction while blocking it in the reverse direction.

Forward Bias in p-n Junction

• When a p-n junction is forward biased, charge carriers are injected into the depletion region, allowing current to flow.

Charge Carrier Movement in Solar Cells

• In thick solar cells, the primary mechanism of charge carrier movement is diffusion.

p-Type Region Material

• The material used for the p-type region in a p-n junction is typically doped with elements like boron.

Light Excitation in Solar Panels

• When light excites electrons in a solar panel, it generates electron-hole pairs, contributing to current flow.

p-n Junction Applications

• p-n junctions are widely used in various applications, including diodes, transistors, and photovoltaic cells.

Test your understanding of electrical properties, including conductance, resistance, and the characteristics of conductors, semiconductors, and insulators. Explore how imperfections, temperature, and deformation affect conductivity in metals and semiconductors. Also, delve into the world of p-n junctions, transistors, and conducting polymers.