Synthesis of ZnS/SiO_2 Core-Shell by Sol-gel Process and Covering then with Gold Nanoparticle and Study of its Photoluminescence Properties

摘要

Semiconductors have been suggested as ideal candidates for many electrical and optical applications and several groups have reported their successful synthesis in recent years. In particular, ZnS that is a direct wide band gap (3.91 eV) semiconductor and an important phosphor host lattice material, can be used in electroluminescent devices (ELD), due to its large band gap, which enables emission of visible light without absorption and efficient electron transport. In this work, we report synthesis and structural characteristics of gold covered core-shell nanometer size of ZnS/SiO_2 thin films as a patterning materials for use as a protective layer in optical phase change discs prepared through a simple sol-gel process. The results obtained by transmission electron microscopy (TEM) images showed that. as prepared core-shell materials were well-aligned nanoprticles grew m the same direction and through X-ray diffraction ( XRD) analysis, we found that ZnS/SiO_2 core shell material was composed of crystalline ZnS core covered by an amorphous SiO_2 shell. Photoluminescence (PL) measurements performed on core-shell samples before and atter gold coverig samples have provided information regarding stoichiometric vacancies or interstitial impurities and enhenced intensity of the green emission of ZnS nanowires at room temperature due to sheelding with SiO_2.