resumo
Upconversion broadband white light emission driven by low-power near-infrared (NIR) lasers has been reported for many materials, but the mechanisms and effects related to this phenomenon remain unclear. Herein, we investigate the origin of laser-induced continuous white light emission in synthesized nanoparticles (Gd0.89Yb0.10Er0.01)(2)O-3 and a mechanical mixture of commercial oxides with the same composition 89% Gd2O3, 10% Yb2O3, and 1% Er2O3. We report their photophysical features with respect to sample compactness, laser irradiation (wavelength, power density, excitation cycles), pressure, temperature, and temporal dynamics. Despite the sensitizer (Yb3+) and activator (Er3+) being in different particles for the mechanical mixture, efficient discrete and continuous upconversion emissions were observed. Furthermore, the synthesized nanoparticles were developed as primary luminescent thermometers (upon excitation at NIR) in the 299-363 K range, using the Er3+ upconversion H-2(11/2) -> I-4(15/2)/S-4(3/2) -> I-4(15/2) intensity ratio. They were also operating as secondary ones in the 1949-3086 K, based on the blackbody distribution of the observed white light emission. Our findings provide important insights into the mechanisms and effects related to the transition from discrete to continuous upconversion emissions with potential applications in remote temperature sensing.
palavras-chave
BROAD-BAND; NANO-POWDERS; LASER; LUMINESCENCE; YB3+; LANTHANIDE; TEMPERATURE; RADIATION; EXCITATION; BEHAVIORS
categoria
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
autores
Ramos, TJS; Longo, RL; Brites, CDS; Ferreira, RAS; Malta, OL; Carlos, LD
nossos autores
Carlos Brites
Professor Auxiliar
Luís Carlos
Professor Catedrático
Maria Rute de Amorim e Sá Ferreira André
Professor Catedrático
Talita Jordanna da Souza Ramos
Estudante de doutoramentoProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). The Brazilian Agencies FACEPE, CNPq, CAPES, and FINEP are acknowledged for providing partial financial support under grants (FACEPE: BFD 0020-1.05/22, PRONEX APQ-0675-1.06/14, APQ-1007-1.06/15), (CNPq: GD 870024/2001-9, PQ 309177/2018-9), (CAPES PDSE: 88881.623514/2021-01).