HgTe, CdTe, (Cd,Hg)Te, Cd(Te,Se), Cd(Te,S), ZnTe, HgSe, CdSe, Cd(Se,S), (Cd,Mn)Se, (Cd,Zn)Se quantum dots-nanocrystals

This chapter II-VI quantum dot I - nanocrystals is confined to data obtained for (almost) spherical quantum dots, i.e. for which the size can be defined by a radius. It summarizes results for II-VI nanocrystals ((HgTe, CdTe, (Cd, Hg)Te, Cd(Te,Se) and Cd(Te,S), ZnTe, HgSe, CdSe, Cd(Se,S), (Cd,Mn)Se and (Cd,Zn)Se) embedded in transparent matrices (glass, polymer, organic solutions, micelle media, porous media etc.) or deposited as isolated nanocrystals on substrates. Preparation methods and theoretical descriptions of energy states are given for HgTe, CdTe, (Cd,Hg)Te, Cd(Te,Se), Cd(Te,S), ZnTe, HgSe, CdSe, Cd(Se,S), (Cd,Mn)Se, and (Cd,Zn)Se. Size-dependent energy states, splitting of states, interaction with phonons, modification of the optical properties by external fields (electroabsorption, electroluminescence, charge transport and photocurrent), external magnetic fields, hydrostatic pressure and impurity states are explained in low-density regime for some of these compounds. Biexciton states, nonlinear optical coefficients, stimulated emission and optical gain are explained in intermediate-density regime. Coherent dynamics, relaxation and recombination of optical excitations (dephasing times and homogeneous linewidth, radiative and nonradiative recombination), dot-dot interactions, and quantum dot arrays are explained in high-density regime.