Microstructural and optical properties of rare earth ions doped TiO2 for potential white LED applications

• Published in: Journal of materials science. Materials in electronics 2018-10, Vol.29 (19), p.16824-16835
• Main Authors: Zikriya, Mohamed, Nadaf, Y. F., Manjunath, C., Renuka, C. G.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Anatase; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Doping; Dysprosium; Energy gap; Europium; Field emission microscopy; Light emitting diodes; Luminescence; Materials Science; Metal ions; Microstructure; Morphology; Optical and Electronic Materials; Optical properties; Optoelectronics; Photoluminescence; Rare earth elements; Scanning electron microscopy; Spectrum analysis; Titanium dioxide; Transmission electron microscopy; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9777-6

Nano ceramics of pure TiO 2 and Dy 3+ , Eu 3+ and Tb 3+ doped TiO 2 are prepared by hydrothermal method and these are characterized by using X-ray diffractometer (XRD), UV–Visible spectroscopy, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopy. XRD analysis revealed that the average particle size of the pure TiO 2 and Dy 3+ , Eu 3+ and Tb 3+ doped TiO 2 are in the range of 45–35 nm and confirms the anatase phase. The FESEM and HRTEM analysis confirm that the obtained ceramics are in nano regime. The absorption spectrum revealed that the bandgap of the TiO 2 ceramics are in the range 3.14–3.2 eV. The PL analysis showed that the doping of Dy 3+ , Eu 3+ and Tb 3+ had improved the luminescence behavior than the pure TiO 2 nanoparticles. Overall, by doping 0.5 mol% concentration of rare earth (RE) greatly alters the structural morphology and directly influence the luminescence behavior of TiO 2 and suitable for advanced optoelectronic applications. The color purity of the studied samples is found to be 91% for Dy 3+ , 84% for Eu 3+ and 73% for Tb 3+ at the excitation of 345 nm, 376 nm and 350 nm respectively. The single-doped sample Eu 3+ : TiO 2 , Tb 3+ : TiO 2 and Dy 3+ : TiO 2 samples showed orange–red, blue–green and white emissions respectively.