| Vacancy-Driven Improvement of Optical and Ferromagnetism in Co²⁺/La³⁺ Dual-Doped ZnS Quantum Dots for Spintronic and Optoelectronic Applications |
| Paper ID : 1093-ISCH |
| Authors |
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Muhammad I Amer * Faculty of Science - Helwan University |
| Abstract |
| For the first time, this study examines the influence of Co2+ and La3+ dual-doped ZnS quantum dots (QDs) on their microstructural, magnetic, and optical properties, relevant to spintronic and optoelectronic applications. A straightforward chemical approach (coprecipitation method) was used to synthesize Zn0.90Co0.1-xLaxS quantum dots (x= 0, 3, 5, and 7 at.%) capped with polyethylene glycol (PEG) to regulate the size of the QDs. A cubic singlephase structure with almost uniform spherical particles averaging around 6-7 nm in size was evidenced by X-Ray Diffractometer (XRD) and High-Resolution Transmission Electron Microscope (HR-TEM), complemented by Selected Area Electron Diffraction (SAED). The XRay Photoelectron Spectroscope (XPS) outcomes showed the incorporation of Cobalt and Lanthanum elements in both the (+2) and (+3) oxidation states, and also highlighted a substantial presence of sulfur vacancies. The tunability of the optical gap energy (Eg) and the optical dispersion parameters (Ed, Eo) has resulted in an improvement of the non-linear optical attributes, thereby supporting their application in optoelectronic devices. Defect-assisted blue emission was monitored through a Photoluminescence (PL) investigation. Furthermore, the dual-doping improves the room-temperature ferromagnetic ordering (RT-FM), possibly mediated by vacancy-induced magnetic polarons. These compelling magnetic results suggest that dual-doped ZnS QDs could pave the way for advancements in spintronic technology. |
| Keywords |
| nanocrystals; diluted magnetic semiconductors; sulfur vacancies; bound magnetic polaron; spintronic and optoelectronic technology |
| Status: Abstract Accepted (Poster Presentation) |