Structural, optical, photoluminescence and electrochemical behaviours of Mg, Mn dual-doped ZnS quantum dots

Mg, Mn dual doped ZnS quantum dots (QDs) have been synthesized via co-precipitation method. XRD results revealed that the dual doped ZnS QDs have a cubic structure without forming secondary phase. The particle size was ranged in ~ 2 nm. TEM study portrayed particle assembly and its agglomeration. The scanning electron microscope (SEM) study showed the surface smoothening on samples for Mg addition. Fourier transform infra-red (FTIR) and energy dispersive x-ray (EDX) analysis evidenced the substitution of Mg into Mn:ZnS QDs. UV–visible studies showed that absorption peak intensity was increased and redshifted, shortening of band-gap with increasing Mg doping concentration. A weak UV emission and strong red emission were received from the photoluminescence (PL) investigations. The electrochemical analysis showed a better electrical property for Mg = 2% concentration. Since Mg = 2% doping ratio offers better optical absorption, PL emission, catalytic properties, these materials shall be selected as a suitable candidate for solar and optoelectronic device applications.