The effect of cobalt ions doping on the optical properties of ZnS quantum dots according to photoluminescence intensity and crystalline structure

The doping of Co2+ into ZnS QD offered a considerable luminescence intensity in the UV region and controlling of the Quantum Dot (QD) size. A performed X-ray diffraction (XRD) study revealed a cubic phase of the d-spacing 0.32 nm for a Co2+ concentration level of 0.005. The grain size varied between 3.9 nm and 7.5 nm for concentrations between 0.001 and 0.01. The obtained photoluminescence (PL) spectrum revealed a dependence of emission intensity and QD bandgap on the dopant concentration. With the help of TEM imaging, it has been shown that the size of the QD was about 4.8 nm. Prepared bulk samples of the Zn0.1-xSCox, with 0.001