Wet chemical approach for the low temperature synthesis of ZnGa2O4:Tb3+ quantum dots with tunable blue-green emission

• Published in: Journal of alloys and compounds 2018-10, Vol.764, p.142-146
• Main Authors: Safeera, T.A., Anila, E.I.
• Format: Article
• Language: English
• Subjects: Display devices; Nano phosphor; Optical material; Quantum dot; Wet chemical synthesis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.06.048

This is the primary report on the formation of blue-green tunable zinc gallate quantum dots, doped with Tb3+ by simple wet chemical method. The synthesis temperature was kept at a low value of 90 °C and only ecofriendly chemicals were used. Effect of Tb3+ concentration on the structural and optical properties were investigated using characterization techniques like x-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance (DRS) and photoluminescence (PL). Quantum dot formation with spinel structure was confirmed from XRD and TEM. Doping led to the introduction of strain in the lattice, verified by Williamson-Hall (WH) plot. There exists a blue shift in band gap energy for every sample due to the quantum confinement effect. Commission Internationale de L'Eclairage (CIE) chromaticity diagram illustrates the transformation from blue to green colour effectively and the critical distance was estimated to be 18 Å. The highly intense green emission observed for the Tb3+ concentration of 4 mol%, may find applications in display devices and biomarkers. [Display omitted] •It is the first time report on the synthesis of green emitting nano ZnGa2O4:Tb3+ by aqueous solution route.•On comparison with previous reports, a low temperature of 90 °C were employed.•The purity and intensity of green emission can be utilized in display and bio-imaging applications.