Synthesis and photoluminescence of Cd_1-xMn_xS (x ≤ 5%) nanocrystals

We report the synthesis of Cd_1-xMn_xS nanocrystals with x ≤ 5%. Special care is taken to determine the final manganese concentration in the nanoparticles. The variation of the photoluminescence spectrum of Cd_1-xMn_xS colloidal solutions as a function of manganese concentration is studied. Characteristic luminescence features such as emission maximum wavelength and lifetime are analyzed. We find that it is possible to isolate contributions from particles containing no, one, or more Mn²⁺ ions. Dopant distribution among the crystallites is random and obeys to a binomial law. The agreement with this simple statistical model allows to use simple photoluminescence experiments to determine Mn²⁺ mean concentration and dispersion in Cd_1-xMn_xS nanocrystals.