Tunable blue-green emission and energy transfer properties in Ba2SiO4:Tb3+ obtained from sol-gel method

Author(s)

Bispo-Jr, A. G. ; Lima, S. A. M. ^{[1, 2]} ; Lanfredi, S. ^{[1, 2]} ; Praxedes, F. R. ^{[1, 2]} ; Pires, A. M. ^{[1, 2]}

Affiliation

^[1] Bispo-Jr, Jr., A. G., Sao Paulo State Univ Unesp, Sch Technol & Sci, R Roberto Simonsen 305, BR-19060900 Presidente Prudente, SP - Brazil

^[2] Bispo-Jr, Jr., A. G., Sao Paulo State Univ Unesp, Inst Biosci Humanities & Exact Sci, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Document type: Journal article
• Source: Journal of Luminescence; v. 214, OCT 2019.
• Web of Science Citations: 2

Abstract

Herein, we introduce an adapted sol-gel synthesis of blue-green-emitting phosphors based on Ba2SiO4:Tb3+, which were obtained in a quite-soft calcination condition (1100 degrees C/2 h) as a monophasic crystalline phase, space group P-mcn (62), characterized by high-agglomerated particles. The optical band gap value decreases as the amount of Tb3+ increases, from 5.65 eV (undoped) to 4.40 eV (5 %-doped). All doped samples are excited by UV radiation (250 nm), emitting in the blue and green spectral region as a result of the Tb3+ transitions arising from the D-5(3) and D-5(4) excited levels, respectively. Yet, the overall emitted color of the phosphor is tuned by the Tb3+ concentration since the increase of the activator amount dislocates the emission color from blue toward green due to a dipole-dipole energy transfer between two close Tb3+ ions. The emission quantum efficiency of the D-5(4) state is a function of the emission intensity and it enhances up to the 4 %-doped sample. A new approach to calculate the D-5(3) state quantum efficiency of Tb3+ is also proposed and these values decrease from 95.3% to 42.4% as the doping amount enhances from 0.1 up to 5%. Thus, both the green-blue color tunability and the high quantum efficiency qualify this material for future photonic applications. (AU)

• FAPESP's process: 12/13876-9 - Optical and Structural effects of Eu(III) doping ion concentration in the Ba2SiO4 host lattice synthesized via sol-gel method
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 16/20421-9 - Tricolor devices based on Ba2SiO4:Eu3+ e/ou Tb3+: sol-gel synthesis and eletrophoretic deposition for W-LEDs application
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 15/10394-1 - LBL luminescent thin films of rare earth doped Ba2SiO4 obtained via sol-gel for white LED application
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships in Brazil - Master