The third generation semiconductor materials refer to the wide band gap semiconductor materials represented by silicon carbide (SIC), gallium nitride (GAN), zinc oxide (ZnO), diamond and aluminum nitride (AlN). Compared with the first and second generation semiconductor materials, the third generation semiconductor materials have wide band gap, high breakdown electric field, high thermal conductivity, high electron saturation rate and higher radiation resistance. Therefore, they are more suitable for making high-temperature, high-frequency, radiation resistance and high-power periods. They are usually also called wide band gap semiconductor materials (band gap width greater than 2.2ev), also known as high-temperature semiconductor materials. It is a key core material and electronic component supporting the innovative development of new generation mobile communication, new energy vehicles, high-speed rail trains, UHV power grid, national defense and military industry.
The full name of two-dimensional material is two-dimensional atomic crystal material. It refers to the material in which electrons can only move freely on the non nano scale of two dimensions. It is a new thing with the successful separation of single atomic layer graphene. There are many kinds of two-dimensional materials, including conductors (such as graphene), semiconductors (such as transition metal chalcogenide two-dimensional materials, indium selenide, etc.) and insulators (such as hexagonal boron nitride). Two dimensional materials have the characteristics of conductivity, heat conduction, optics and chemistry that materials do not have in the macro scale. Therefore, field effect transistors, photoelectric devices, thermoelectric devices and other fields have broad application prospects, and have triggered a wave of scientific and technological competition in many fields such as global academia, new materials, electronic semiconductors and so on.
Graphene is a kind of substance composed of carbon atoms in the form of sp ² The hybrid orbitals form a hexagonal two-dimensional carbon nanomaterial with honeycomb lattice. Graphene has excellent optical, electrical and mechanical properties. It has important application prospects in materials science, micro nano processing, energy, biomedicine and drug delivery. It is considered to be a revolutionary material in the future. Andre Geim and Konstantin Novoselov, physicists at the University of Manchester in the UK, successfully separated graphene from graphite by micromechanical stripping method, so they jointly won the 2010 Nobel prize in physics. The common powder production methods of graphene are mechanical stripping method, redox method and SiC epitaxial growth method, and the film production method is chemical vapor deposition (CVD).
As one-dimensional nano materials, carbon nanotubes have light weight, hexagonal structure and perfect connection. They have high-quality properties such as good conductivity, super tensile property, good thermal conductivity and strong adsorption. It can be widely used in the fields of conductive paste for lithium battery, solar cell coating, high-strength structural material, conductive coating, catalyst carrier, field emission material, electromagnetic shielding material and so on.