Luminescent Electrochromic Devices for Smart Windows of Energy-Efficient Buildings
Mariana Fernandes,
Vânia Freitas,
Sónia Pereira,
Rita Leones,
Maria Manuela Silva,
Luís D. Carlos,
Elvira Fortunato,
Rute A. S. Ferreira,
Rosa Rego,
Verónica de Zea Bermudez
Affiliations
Mariana Fernandes
Department of Chemistry and CQ-VR, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal
Vânia Freitas
Department of Physics and CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
Sónia Pereira
CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa and CEMOP-UNINOVA, 2829-516 Caparica, Portugal
Rita Leones
Department of Chemistry, University of Minho, Gualtar, 4710-057 Braga, Portugal
Maria Manuela Silva
Department of Chemistry, University of Minho, Gualtar, 4710-057 Braga, Portugal
Luís D. Carlos
Department of Physics and CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
Elvira Fortunato
CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa and CEMOP-UNINOVA, 2829-516 Caparica, Portugal
Rute A. S. Ferreira
Department of Physics and CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
Rosa Rego
Department of Chemistry and CQ-VR, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal
Verónica de Zea Bermudez
Department of Chemistry and CQ-VR, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal
To address the challenges of the next generation of smart windows for energy-efficient buildings, new electrochromic devices (ECDs) are introduced. These include indium molybdenum oxide (IMO), a conducting oxide transparent in the near-infrared (NIR) region, and a NIR-emitting electrolyte. The novel electrolytes are based on a sol-gel-derived di-urethane cross-linked siloxane-based host structure, including short chains of poly (ε-caprolactone) (PCL(530) (where 530 represents the average molecular weight in g mol−1). This hybrid framework was doped with a combination of either, lithium triflate (LiTrif) and erbium triflate (ErTrif3), or LiTrif and bisaquatris (thenoyltrifluoroacetonate) erbium (III) ([Er(tta)3(H2O)2]). The ECD@LiTrif-[Er(tta)3(H2O)2] device presents a typical Er3+ NIR emission around 1550 nm. The figures of merit of these devices are high cycling stability, good reversibility, and unusually high coloration efficiency (CE = ΔOD/ΔQ, where Q is the inserted/de-inserted charge density). CE values of −8824/+6569 cm2 C−1 and −8243/+5200 cm2 C−1 were achieved at 555 nm on the 400th cycle, for ECD@LiTrif-ErTrif3 and ECD@LiTrif-[Er(tta)3(H2O)2], respectively.
