Structural and Optical Properties of Zn_(0.98)T_(0.02)S (T=Mn, Cu, Ni, Co, Cr, Cd Sn) Quantum dots: A Comparative Study

摘要

Zn_(0.98)T_(0.02)S (T= Mn, Cr, Cu, Ni, Co, Cd &Sn)quantum dots (QDs) were prepared successfully using co-precipitation method at room temperature. The properties of lightly doped (T = 2 %) ZnS were compared with various transition metal ions doping. The synthesized samples were analyzed using x-ray diffraction study and transmission electron microscopic study. From the structural analysis, it was noted that all the samples were exhibited cubic structure except Cu dopedZnSQDs. The particles size was estimated and they exhibitedwithin the range of 2-3nm. TEM pictures supported for identification of the spherical structure of particles and size of the particles.EDX analysis confirmed the presence of elements in prepared samples. UV- visible absorption and transmission studies evidenced the optical properties of samples. The optical band gap was calculated for each sample and they were in the range of 3.5eV to 4.00eV. The reason for blue shift and red shift on band gap was discussed based on size effects and electron transition between d shells. This comparative analysis will support to the material selection for optoelectronic device fabrication.