Altere d Lumines cence Efficiency of Cadmium Sulphide Quantu m Particle s via co-dopi ng NixZny ions

Nanosize d semicond uctor materials have drawn significant attention due to their uniq ue optical a nd chemic al properties originating from the quantum c onfinement effect [۱,۲ ]. Doped m aterials show different type of luminescence properties which are strongly depend ed on the ty pe of dopa nt ions. These dopant i mpurities play an impor tant role in changing t he electronic structure and transition probabilities of the host mater ial [۳]. In this work, w e report the synthesis of single/do uble impur ity (Ni:Zn) doped CdS quantum do ts at ambient temperature by wet- chemical m ethod. Doped Cd۱-x-yNixZnyS Q-dot s were synth esized by t he procedure reported i n our previously work [۴ -۶].Results and Discussion:The absorption edge of bulk CdS is at ۵ ۱۵ nm [۴]. U V-vis of do ped and co-doped CdS is shown in Fig. ۱ (left graph). The excitonic transition re d-shifts and becomes l ess prominent on doping. The red shift indicates the formation of larg er particles on doping. Furthermore, for calculating the direct band g ap value (Įh ȣ) ۲ as a fun ction of hȣ is plotted a nd it is show n in Fig. ۱ (right graph ). From the value of band gap shift and using Brus model [۱] the size of nanoparticles have been calculated and those are shown in inset Fig. ۱ (right graph).