Structure dependent photoluminescence and magnetic properties of Co:ZnS nanostructures

Abstract

Co:ZnS nanostructures have been synthesized via the solvothermal method by modifying the stoichiometry of Zn and S sources in the solvothermal process. The structure and morphology analysis demonstrates that the increase of the Zn/S molar ratio leads to changes in the morphology and structure, from Co:ZnS nanorods and hexagonal nanocrystals to core–shell Co:ZnS/ZnO nanocrystals. The photoluminescence spectrum for Co:ZnS/ZnO exhibits strong visible light emissions due to the presence of a large amount of structural defects, whereas the emissions for Co:ZnS nanorods almost disappear because of the high crystallinity. All the samples display obvious room-temperature ferromagnetism. The saturated magnetic moment of the samples strongly depends on the concentration of structural defects in the nanostructures and can be effectively enhanced by the introduction of abundant defects.

Structural, optical, magnetic and half-metallic studies of cobalt doped ZnS thin films deposited via chemical bath deposition

“…In 2012, a study was published regarding the deposition of hexagonal cobalt doped ZnS thin films via pulsed laser deposition, 2 and the growth of cobalt doped ZnS nanoparticles using the colloidal method including the investigation of optical and magnetic properties. [3][4][5][6][7] Other methods to deposit/synthesize doped ZnS films and nanocrystals include: the aqueous method, 6 chemical bath deposition, 7,8 refluxing technique, 9 precipitation method, 10,11 pulsed laser ablation, 12 solid state reaction method, 13 solvothermal technique 14 and hydrothermal method, 15,16 aerosol assisted chemical vapour deposition and colloidal thermolysis. [17][18][19][20][21][22][23][24] Among these, CBD is the simplest and most cost effective method to synthesize thin films and nanocrystals.…”

Synthesis and characterization of ZnS-based quantum dots to trace low concentration of ammonia

“…These materials are very useful in designing short-wavelength LEDs, electroluminescence devices, sensors, laser diodes, flat panel display, biological imaging, solar cells, optoelectronic devices and labelling [2−7] . There are numerous approaches to fabricate nanoparticles (quantum dots), such as the aqueous method [8] , chemical bath deposition [9,10] , refluxing technique [11] , pulsed laser ablation [12] , solid-state reaction method [13] , solvothermal technique [14] , hydrothermal method [15,16] , co-precipitation and colloidal thermolysis and aerosol assisted chemical vapor deposition [17−22] . Among all these approaches, co-precipitation is the uncomplicated and cost-efficient method.…”