1. intrinsic semiconductors

Conductor: The outermost layer of electrons is prone to directed movement under the action of an external electric field.

Insulator: The outermost electrons of an atom are strongly bound by the nucleus and conductive only when the outer electric field is strong to a certain extent.

Semiconductors: Between conductor and Insulator

 

Intrinsic semiconductors: Pure Crystalline (stable) Semiconductors

Common semiconductor materials include four-price silicon and Ge (zh release)

Carrier: the particles carrying the charge are carriers (holes and free electrons)

 

 

Temperature Characteristics:

1. Due to hot motion, the price electrons with enough energy break free from the bound of the bond and become free electrons, with negative electricity.

Composite: free electrons and holes in motion disappear simultaneously (with a probability). It is understood as: free electrons come back.

Think: Why does the hole band have positive and free electronic bands have negative power?

The atom is neutral and runs a free electron with negative power, and the rest is the positive power.

2. The higher the temperature, the more electrons you break free from. The higher the concentration of free electrons and holes (more carriers), the higher the conductivity.

Dynamic Balance: when the temperature is set, the number of free electrons and holes is equal.

Thinking: When is it not conductive?

Non-conducting when the thermodynamic temperature is 0 K (minus 273 ℃)

Conclusion: The conductivity of intrinsic semiconductors is closely related to the temperature.

 

Electric Conductivity: When an electric field is added, the free electrons with negative electricity and the holes with positive electricity participate in the conductivity. due to the small number of carriers, the conductivity is poor.

 

Summary:

Why do semiconductors need to be made into intrinsic semiconductors with poor conductivity?

Controllable material conductivity

 

1. intrinsic semiconductors