Simulation-Based Optical Spectra Analyses and Synthesis of Highly Monodispersed Mn-Doped ZnSe Nanocrystal

Abstract

Geometrical structures of (ZnSe)n, n=3x, (x= 1-4) and (MnxZn2xSe3x), (x=1-4) clusters were calculated using density functional theory (DFT). Optical/absorption spectra, Raman spectra, HOMO-LUMO gap energy and binding energy of each cluster were calculated. The calculated results show the red shift of the optical/absorption spectra band caused by the manganese atoms doped in ZnSe clusters, and the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap energy value is decreased. Furthermore, we realized highly monodispersed manganese-doped zinc selenide quantum dots (Mn:ZnSe d-dots) experimentally by using a convenient route. The as-synthesized Mn:ZnSe d-dots were characterized by UV-Vis absorption, photoluminescence (PL), X-ray diffraction (XRD), TEM and HRTEM. The experimental results revealed that the as-prepared Mn:ZnSe d-dots with zinc-blende structure have an average size of about 3.9 nm.