resumo
The technological potential of poly(methyl methacrylate) (PMMA)-based composite films doped with lanthanide-doped sol-gel derived ionosilicas (IS-Ln) previously proposed for luminescent down-shifting (LDS) and luminescent solar concentrator (LSC) layers connected to photovoltaic (PV) cells is extended here to electrochromic devices (ECDs), targeting the fabrication of single energy harvesting/conversion/management LSC-LDS/PV/ECD systems. These integrated devices have foreseen application in the windows of future zero-energy buildings of smart cities. The proof-of-concept is given with the report of the electro-optical performance of an ECD comprising an optimized electrolyte film composed of PMMA, IS-Nd, and IS-Eu, and the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. This amorphous electrolyte is stable below 160 degrees C, exhibits high ionic conductivity (2.13 x 10(-4) and 8.76 x 10(-4) S cm(-1) at room temperature and 44 degrees C, respectively), and emits in the visible (red color) and near-infrared (NIR) spectral regions. The device demonstrated fast switching speed (50 s) and high transparency in the visible-to-NIR spectral regions (transmittance (T) = 79/96/89/77% at 555/1000/1500/1650 nm in the as-prepared state, respectively). Upon application of +/- 2.5 V for 200 cycles, at the same wavelengths, the T-bleached/T-colored values were 44/28, 46/26, 39/20, and 27/9%, respectively, and the coloration efficiency (CE) values CEin/CEout values were -302/+181, -381/+228, -446/+267 and -734/+440 cm(2) C-1, respectively.
palavras-chave
IONIC LIQUIDS; CELL EFFICIENCY; SMART WINDOWS; ENERGY; ELECTROLYTES; PERFORMANCE; MODULATION; BUILDINGS
categoria
Materials Science
autores
Cardoso, MA; Correia, SFH; Goncalves, HMR; Pereira, RFP; Pereira, S; Maria, TMR; Silva, MM; Valente, AJM; Fortunato, E; Ferreira, RAS; Bermudez, VD
nossos autores
Maria Rute de Amorim e Sá Ferreira André
Professor Catedrático
Marita Alves Cardoso
Estudante de doutoramento
Sandra Filipa Henriques Correia
InvestigadorProjectos
Solar-Powered Smart Windows for Sustainable Buildings (SOLPOWINS)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
agradecimentos
This work was supported by National Funds by FCT-Foundation for Science and Technology and, whenever applicable, by FEDER funds through the POCI-COMPETE 2020-Operational Program Competitiveness and Internationalization in Axis I-Strengthening research, technological development, and innovation (UIDB/00616/2020, UIDP/00616/2020, UID/QUI/00686/2020, UID/QUI/00313/2020, UIDB/50006/2020, SOLPOWINS-PTDC/CTM-REF/4304/2020, OBTAIN-NORTE-01-0145-FEDER-000084, and PTDC/BTM-MAT/30858/2017). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by Portuguese funds through the FCT/MCTES. MA Cardoso acknowledges FCT for Ph.D. grant SFRH/BD/118466/2016 and SFH Correia acknowledges SolarFlex (CENTRO-01-0145-FEDER-030186).