Abstract
Cd1-xDyxSe nanocrystalline quantum dots were synthesized via cation exchange approach for the first time. The as-synthesized Cd1-xDyxSe nanocrystals showed a cubic phase at all Dy ion contents. The formed nanoparticles of the as-synthesized Cd1-xDyxSe nanocrystals were spherical like shape and their diameters increased from 2.1–7.3 nm with increasing the amount of Dy ions. The doping of CdSe with Dy atoms comprises a read shift of the optical absorption spectral curves. Therefore, a decrease of the optical band gap from 2.58 eV to 2.15 eV owing to the increase of Dy atoms took place. The partial substitute of the Cd atoms by Dy atoms instigated remarkable enhancing of the of luminescent intensities by eight order of magnitudes, made the PL peaks more sharper by four orders and achieved enlargement of the quantum yield to reach to value of 93 %. A decrease of the Stokes shift due to the doping by the Dy atoms was reasoned to the passivation of the defects. The enlargement of luminescence intensity, the creation of narrow emission band and the high quantum yield value empowered the as-synthesized Cd1-xDyxSe nanocrystals to be employed as laser materials for the manufacturing of multicolor laser diodes.