Structure and Optical Properties of Nanocrystals and Quantum Dots with Diamond, Lonsdaleite, Sphalerite and Wurtzite Structures

The formulas for calculation of the number of atoms and their space distribution in nanocrystals and quantum dots with symmetry of diamond, lonsdaleite, sphalerite, and wurtzite structures are reported. The numbers of atoms are determined by six structurally invariant numbers and the symmetry group of order h. The atom densities of such structures are established as well as their dependences from quantum dots size. Optical properties and the change of the emission wave length from sizes of quantum dots with sphalerite and wurtzite structures are considered. Because the properties of quantum dots depend on their size dispersion formula of quantum dots with diamond and lonsdalait structures is proposed.