Novel building Integration Designs for increased Efficiencies in Advanced Climatically Tunable Renewable Energy Systems

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Novo modelo de integração de sistemas avançados de energia renovável nos edifícios

Publication . Aelenei, Laura Elena; Brites, Maria João; Joyce, A; Esteves, M. Alexandra; Rodrigues, Carlos; Barros, Helio; Valente, D.

RESUMO: O projeto IDEAS “Novel building Integration Designs for increased Efficiencies in Advanced climatically tunable renewable energy Systems” é um projeto financiado pelo Programa HORIZON2020, multidisciplinar que reúne várias temáticas científicas e competências para o desenvolvimento e demonstração de um novo conceito de design para integração de edifícios. O modelo combina várias tecnologias de energia renovável, incluindo solar fotovoltaica, solar térmica, armazenamento de energia térmica e bombas de calor (aerotérmica e geotérmica) acopladas a piso radiante. No presente trabalho os autores querem partilhar a visão e descrição geral do projeto IDEAS, alguns trabalhos que foram desenvolvidos nas primeiras atividades e tarefas do projeto relativamente à fabricação e testes de camadas luminescentes downshifting (LDS) para o módulo fotovoltaico híbrido PVT com concentrador parabólico composto (CPC), bem como apresentar o modelo numérico de todo o sistema IDEAS que se encontra em desenvolvimento para a análise técnico económica do sistema IDEAS.

2020-11Conference object

Open access

Synthesis and photophysical properties of tetraphenylethylene derivatives as luminescent downshifting materials for organic photovoltaic applications

Publication . Barros, Helio; Esteves, M. Alexandra; Brites, Maria João

ABSTRACT: Luminescent Down-Shifting (LDS) is an optical approach applied in several photovoltaic (PV) technologies in which high energy solar radiation is converted to a wavelength region where the response of the photovoltaic devices is better. The use of LDS layers on organic photovoltaics (OPV) could serve two purposes: to prevent cell degradation by filtering the incident ultraviolet (UV) radiation and to improve the spectral response of PV cells at short-wavelength. This work reports, the design and synthesis of a series of tetraphenylethylene (TPE) derivatives based on TPE-A or A-pi-TPE-pi-A molecular structure featuring various electron-acceptor (A) groups. The photo-physical properties of the new LDS compounds were systematically studied in 1,4-dioxane solution and film (Zeonex) by UV-visible absorption and fluorescence spectroscopy, and electrochemical properties studied by cyclic voltammetry. Thermal stability of the new LDS compounds was evaluated by Thermogravimetric analysis (TGA). Theoretical computational studies provided evidence of existence of intramolecular charge-transfer (ICT) between frontier orbitals of donor and acceptor moieties. The good photophysical and thermal properties of the synthesized TPE derivatives, associated with high molar absorption coefficients in UV spectrum and emission maximum in the range of 476-531 nm, make them promising candidates for LDS layers in OPV application.

2021-11Journal article

Open access

Synthesis, photophysical and electrochemical properties of π-conjugated pyrene based down-shifting molecules with fluorinated aryl groups

Publication . Barros, Helio; Esteves, M. Alexandra; Brites, Maria João

ABSTRACT: Pyrene molecule, with excellent photophysical properties (strong absorption cross section, excellent emission properties and a long-excited state lifetime), excellent thermal and photochemical stability, has been widely used as a building block for the synthesis of pyrene-based fluorophores for optoelectronic applications. In this work, we report the synthesis of two series of pyrene-pi-A compounds, series I (3-6) and II (10-13), in which nitro, cyano, cyanoacrylonitrile and cyanoacrylic acid as electron acceptor groups are connected to the pyrene core via aryl or fluoroaryl pi-conjugating bridges. The incorporation of fluorine atom on the pi-extension bridge cause a slightly red-shift at emission wavelength (lambda em) in solution and polymethylmethacrylate (PMMA) films and in-crease the Stokes shift due to greater stabilization of molecular orbitals in the excited state, especially for series I. Solvatochromic measurements and theoretical computational studies suggest a higher intramolecular charge transfer in the excited state for series II when compared to series I due to their stronger electron acceptor moieties. All pyrene derivatives are stable and exhibited initial mass loss at temperature above 200 degrees C. The good photophysical and thermal properties of the synthesized pyrene derivatives, associated with high molar ab-sorption coefficients in the UV spectrum and good fluorescence emission in the range of 430-480 nm (series I) and 505-567 nm (series II) in PMMA films, make them possible candidates for organic light-emitting diode (OLED) and luminescent down-shifting (LDS) layers for stable perovskite solar cells, respectively.

2023-05Journal article

Open access