Paramagnetic nature of Mn doped ZnS nano particles in opto electronic device application

摘要

Manganese (Mn~(2+)) doped ZnS nano sized powder was prepared by co precipitation method with different concentration from 1 to 5 %. The X-ray diffraction pattern indicates that the prepared powders are in cubic structure with the crystallite sizes lie in the range of 10-12 nm. Diffuse reflectance studies enlightens that an increment in the band gap (3.38-3.55 eV) with increasing dopant. The morphology and size of the sample could be intuitively determined by field emission scanning electron microscope and it shows that ZnS and Mn doped ZnS nanoparticles are appeared as spherical shape. The replacement of Zn by Mn is confirmed by energy dispersive analysis. TEM images confirm the spherical shape of the nanoparticles and SAED images exhibit the crystalline nature and confirm the cubic nature of the synthesized samples. The prepared luminescent nanoparticles of Mn doped ZnS have emission peak at around 617 nm. The symmetry and electronic structure of the Mn doped samples are studied with electron paramagnetic resonance.The paramagnetic nature of Mn doped ZnS nano particles are validated by using vibrating sample magnetometer spectra at room temperature. Thermal analysis measurement of the samples shows that the thermal stability of Mn doped ZnS is higher than the undoped ZnS. This corroborates that ZnS:Mn doping is attributed to the removal of water and it enhanced the crystallinity.