Explanation

It is a kind of nanocrystal small enough to show quantum confinemem effect. quantum dots is a typical zero dimensional nano materials, and the movement of carriers in three spatial directions is limited. Because electrons and holes are quantum confined, the continuous band structure becomes a discrete energy level structure with molecular characteristics, which can emit fluorescence after being stimulated. The synthesis methods of quantum dots mainly include chemical solution growth method, epitaxial growth method, electric field constraint method, etc. Chemical solution method refers to the mixing and heating reaction of precursor, surfactant and solvent to generate corresponding quantum dots materials. The quantum dots prepared by this method have the advantages of low production cost, high yield and high luminescence efficiency, but their electric conductivity is extremely low. epitaxial growth refers to the growth of new crystal on a backing materials. If the crystals are small enough, quantum dots will be formed. According to different growth mechanisms, this method can be subdivided into chemical vapor deposition and molecular beam epitaxy. The electric field constraint method means that the energy level in the crystal is distorted by fully using the electric potential of the metal electrode to form a constraint on the carrier. This method has the highest cost and lowest yield, but because of its high controllability, this quantum dots is most suitable for quantum computing. The unique properties of quantum dots are based on its own quantum confinemem effect, and it has extremely broad applications in nonlinear optics, magnetic media, catalysis, medicine and functional materials.

Classification