First generation semiconductors?
Representative materials: silicon (Si), germanium (Ge). Disadvantages of germanium: poor thermal stability. Germanium transistors appeared in 1948. From 1950 to the early 1970s, germanium transistors developed rapidly. After that, they began to be gradually eliminated from developed countries. By 1980, as the manufacturing process of high-purity silicon gradually matured, they were almost completely replaced by silicon transistors worldwide.
Second generation semiconductors?
Representative materials: gallium arsenide (GaAs), indium phosphide (InP).
Advantages:
1. High electron mobility;
2. Direct band gap, very efficient in optoelectronic applications, because electrons can jump directly and release photons at the same time, such as LEDs and lasers.
Third generation semiconductors?
Representative materials: silicon carbide (SiC), gallium nitride (GaN), zinc selenide (ZnSe).
Advantages: wide bandgap, high breakdown voltage and high thermal conductivity. Suitable for high temperature, high power and high frequency applications.
Fourth generation semiconductors?
Representative materials:
Gallium oxide (Ga2O3), diamond (C), aluminum nitride (AlN) and boron nitride (BN), etc. Advantages: ultra-wide bandgap; high breakdown voltage; high carrier mobility, etc.
Disadvantages:
difficult material growth and preparation; immature manufacturing process, many key technologies have not yet been fully broken through.
