Effect of Ag doping on structural and optical properties of ZnSe nanophosphors

In the present study undoped ZnSe and silver doped ZnSe viz. Zn1−xAgxSe (x=1%, 3%, 5%) nanophosphors are synthesized via a simple hydrothermal route. The prepared nanophosphors were characterized by X-ray diffraction (XRD), UV–vis spectroscopy, Photoluminescence (PL) spectroscopy, Raman spectroscopy and field emission scanning electron microscopy (FE-SEM). XRD patterns of samples reveal the formation of cubic phase for the undoped ZnSe, 1% and 3% Ag doped ZnSe, and 5% silver doped sample indicates the formation of another phase of Ag2Se along with the original one. The crystallite size is found to increase from 4.2 nm to 13.5 nm for Ag doped ZnSe nanostructures. Some nanorods structures are formed in Zn0.95Ag0.05Se as confirmed by the FE-SEM images. The UV–vis analysis shows a blue-shift of the absorption edge of the undoped ZnSe and Ag doped ZnSe nanophosphors as compared to its value for bulk ZnSe. The gradual decrease in PL intensity with increased amount of Ag doping in the host ZnSe nanophosphors is explained on the basis of concentration quenching mechanism.