Photoluminescence properties of nanocrystalline ZnS on nanoporous silicon

Abstract

This paper embodies the report on the microwave solvothermal synthesizing of nanocrystalline ZnS particles for optoelectronic device. The effect of different parameters such as time, temperature, solvents, molar ratio of zinc and thiourea on the phase(s) formation of nanocrystalline Zinc Sulphide was investigated. The obtained nanosize ZnS materials were characterized by the X-ray diffraction, Optical absorption measurements, TEM and Photoluminescence studies. The crystallite size of the ZnS nanoparticles was estimated from the X-ray diffraction pattern by using Scherrer's formula. The as prepared material was obtained in the cubic phase, which showed a perfect match with the earlier reports. The Optical absorption edge of ZnS were blue shifted from the absorption edge of bulk ZnS. The estimated band gap value of ZnS was 4.01 eV. The ZnS nano materials were coated on nano porous silicon by screen-printing technique. Luminescence studies indicated room temperature emission in the wavelength ranges from 422.6 to 612 nm, which cover the blue emission to red emission. The emitted light that depending on the created pore size from porous silicon and the size of the ZnS nano particles.