Photoluminescence of Eu3+-doped CaZrO3 red-emitting phosphors synthesized via microwave-assisted hydrothermal method

Author(s)

Macedo, Wagner Costa ; Bispo Junior, Airton Germano ; Rocha, Kleper de Oliveira ; de Souza Albas, Agda Eunice ; Pires, Ana Maria ; Teixeira, Silvio Rainho ; Longo, Elson

• Document type: Journal article
• Source: MATERIALS TODAY COMMUNICATIONS; v. 24, p. 8-pg., 2020-09-01.

Abstract

Eu-doped 1, 3 and 5 % CaZrO3 red-emitting phosphors were synthesized for the first time using the microwave-assisted hydrothermal method followed by heat treatment at 1200 degrees C. After the crystallization, the orthorhombic CaZrO3 and the non-stoichiometric cubic Ca0.15Zr0.85O1.85 phases were identified for all samples, and the portion of the non-stoichiometric phase increases as the Eu3+ concentration increases. The excitation spectra of the phosphors display Eu3+ f-f excitation bands (namely at 395 nm and 464 nm) and the Eu3+ -> O-2 charge transfer band at 250 nm, confirming that the CaZrO3 host acts as sensitizer for the Eu3+ luminescence. Likewise, the emission spectra feature the typical Eu3+ emission within the red spectral region, displaying CIE color coordinates of (0.642; 0.332), (0.663; 0.330) and (0.668; 0.327) for the 1, 3 and 5 % doped samples, respectively, indicating high emission color purity. By using Eu3+ as spectroscopic probe, the high-resolution selective emission spectra (14 K) confirm that Eu3+ replaces Ca2+ and Zr4+ local sites in both CaZrO3 and the Ca0.15Zr0.85O1.85 phases. Finally, the high absolute emission quantum yield of the 3 %-doped phosphor found at 393 nm (0.29 +/- 0.03) confirms its potential application as red-emitting phosphor, especially in rapid identification of latent fingerprints, security ink or as red-emitting coating of near-UV LEDs for WLED applications. (AU)

• 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: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 17/21995-1 - Tricolor devices based on Ba2SiO4:Eu3+and/or Tb3+: sol-gel synthesis and eletrophoretic deposition for W-leds application
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)