resumo
This manuscript reports the synthesis and characterization of the first organic-inorganic hybrid material exhibiting efficient multimodal spectral converting properties. The nanocomposite, made of Er3+, Yb3+ codoped zirconia nanoparticles (NPs) entrapped in a di-ureasil d-U(600) hybrid matrix, is prepared by an easy two-step sol-gel synthesis leading to homogeneous and transparent materials that can be very easily processed as monolith or film. Extensive structural characterization reveals that zirconia nanocrystals of 10-20 nm in size are efficiently dispersed into the hybrid matrix and that the local structure of the di-ureasil is not affected by the presence of the NPs. A significant enhancement in the refractive index of the di-ureasil matrix with the incorporation of the ZrO2 nanocrystals is observed. The optical study demonstrates that luminescent properties of both constituents are perfectly preserved in the final hybrid. Thus, the material displays a white-light photoluminescence from the di-ureasil component upon excitation at UV/visible radiation and also intense green and red emissions from the Er3+ - and Yb3+ - doped NPs after NIR excitation. The dynamics of the optical processes were also studied as a function of the lanthanide content and the thickness of the films. Our results indicate that these luminescent hybrids represent a low-cost, environmentally friendly, size-controlled, easily processed and chemically stable alternative material to be used in light harvesting devices such as luminescent solar concentrators, optical fibres and sensors. Furthermore, this synthetic approach can be extended to a wide variety of luminescent NPs entrapped in hybrid matrices, thus leading to multifunctional and versatile materials for efficient tuneable nonlinear optical nanodevices.
palavras-chave
UP-CONVERSION MECHANISMS; NEAR-INFRARED LIGHT; PLANAR WAVE-GUIDES; EMISSION RED-SHIFT; X-RAY-ABSORPTION; GEL THIN-FILMS; UPCONVERTING NANOPARTICLES; ORGANIC/INORGANIC HYBRIDS; ZIRCONIA STABILIZATION; ER3+-ZRO2 NANOCRYSTALS
categoria
Science & Technology - Other Topics; Materials Science; Physics
autores
Julian-Lopez, B; Gonell, F; Lima, PP; Freitas, VT; Andre, PS; Carlos, LD; Ferreira, RAS
nossos autores
agradecimentos
Financial support for this work was provided by the Portuguese and Spanish governments (bilateral actions Ref. E92 and PRI-AIBPT2011-1010, and MAT2011-27008 project), as well as University Jaume I (UJI, P1 1B2014-21). This work is supported by the project CICECO-Aveiro Institute of Materials (FCT UID/CTM/50011/2013) and Instituto de Telecomunicaceos (UID/EE/50008/2013), financed by Portuguese funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. F. Gonell and V. Freitas thank Spanish MECD and FCT (SFRH/BD/87403/2012), respectively for their PhD fellowships. This work is included in a collaborative project framed in the European MP1202: HINT COST action. Serveis Centrals d'Instrumentacio Cientifica (SCIC, UJI) is also acknowledged for providing equipment facilities.