The nanoparticles of cadmium sulfide (CdS) doped with various concentration of manganese (Mn) were
synthesized by wet chemical route and characterized by TEM and XRD techniques. The average particle size found by
TEM is 4.256 nm and XRD gives regularity of atoms up to about 2 nm only. The absorption spectra show absorption edge
at 448 nm for all the samples. From the increased effective band gap as 2.76 eV, the particle size was estimated by theory
and is found to be nearly same as that obtained by TEM.
The Voltage dependence of electroluminescence (EL) brightness of the CdS:Mn shows exponential increase. The linear
voltage-current characteristic indicates ohmic nature. The EL brightness at a particular voltage is found to increase by
increasing Mn doping up to 1.0 %, but for higher percentage of Mn the EL brightness is reduced. It is also seen that Mn
does not influence the threshold voltage.