Photoluminescence of highly doped Cd1−xMnxS nanocrystals

We have synthesized CdS and Cd0.7Mn0.3S nanocrystals with diameters of about 4.5 nm. These materials have been studied using photoluminescence spectroscopy with various excitation energies in the temperature range from 1.8 to 300 K. We registered surface and defect states as well as two Mn2+ energy levels that correspond to Mn2+ ions in two different crystal environments. In addition, the resonant behavior of one Mn state excited by 514.5 nm wavelength of laser light has been clearly observed in obtained spectra. We proposed the scheme of energy levels and transitions that explain obtained experimental results.