Versatile properties of CaGd₂ZnO₅:Eu³⁺ nanophosphor: its compatibility for lighting and optical display applications

Abstract

Red color-emitting CaGd2ZnO5:Eu(3+) (CGZO:Eu(3+)) nanophosphors were synthesized by a facile sol-gel process. The structural and luminescent properties of these phosphors were investigated as a function of annealing temperature and Eu(3+) ion concentration. The orthorhombic phase was confirmed at different annealing temperatures, showing an irregular morphology within the nanoscale range. Photoluminescence (PL) excitation spectra of CGZO:Eu(3+) showed host absorption band (HAB), charge transfer band (CTB), and intense f-f transitions of Eu(3+) in the violet and blue wavelength regions. The CTB intensity increased and the HAB intensity decreased with increasing annealing temperature or Eu(3+) ion concentration. The CGZO:Eu(3+) exhibited a strong absorption in the blue region as compared to the CTB and had a superior property compared to available commercial phosphors. This feature facilitates the fabrication of high color rendering index white light-emitting diodes for display systems. In PL spectra, an intense red emission was observed due to the hypersensitive (5)D0→(7)F2 transition with good asymmetry ratio and chromaticity coordinates. Optimized annealing temperature and concentration of Eu(3+) ions were observed for CGZO host lattice based on the 466 nm excitation wavelength. The cathodoluminescent properties were also similar to the PL results.

Synthesis and Characterization of ZnO-SiO2 Composite Using Oil Palm Empty Fruit Bunch as a Potential Silica Source

“…It started to decrease from 1000 to 1400 °C because the formation of Zn2SiO4 started to collapse at higher temperatures in the ZnO-SiO2 composite. The absorption edges became smaller and, thus, decreased the optical band gap [32][33][34]. On the other hand, the obtained optical band gap value is in agreement with a previous study where pure SiO2 was used [35], which resulted in the band gap being indirect.…”

Polysiloxane Functionalized Carbon Dots and Their Cross-Linked Flexible Silicone Rubbers for Color Conversion and Encapsulation of White LEDs

“…Currently, commercial white LEDs (WLEDs) are mostly based on blue LEDs with YAG:Ce yellow phosphors as a color conversion layer (CCL) dispersing in the silicone or polymer matrix that are often used as packaging materials in the LED industry. However, there are certain disadvantages of phosphors like light blocking, leaking, , and even relatively low color quality, , and their poor compatibility with packaging resin, which were crucial factors in the application of WLEDs. On the other hand, these phosphors generally involve expensive rare earth ions that are resource-restricted and not environmentally friendly .…”

Luminescence properties of Dy3+ ions activated novel warm white-light emitting CaGd2ZnO5 nanophosphors

“…1(a) shows the XRD patterns of the CGZO:1Dy 3 þ nanophosphor annealed at 1200 ºC. According to our earlier reports [15,16], the optimal annealing temperature was found to be at 1200 ºC and the dilute concentrations of doping ions did not show any considerable effect on the crystallite size and phase purity [16]. Recently, Xu et al [17] reported the crystal structure of the novel CGZO host lattice, but the JCPDS card is not available till now.…”