Hybrid materials for solar energy harvesting and sustainable building integrated systems

Abstract

Tackling energy consumption in European buildings and reducing its negative impact is vital, and this has been a key driver for the development of new technological solutions for architectural applications targeting a more efficient use of energy resources. Integrated solar energy systems for zero-energy buildings holds the best potential to meet this objective and foster the renewable energy market, but there are steppingstones that limit large-scale industrialization process operation and market implementation at competitive costs. In parallel to the evolution of solar energy harvesting and storage technologies, one of the major challenges has been the quest for materials that convert sunlight in an efficient and cost-effective way, without compromising the perception of colors and thermal comfort inside the buildings. Here we describe the development of functionalized silica-based polymeric coatings for the conversion of solar energy into electricity and smart climatization of buildings, with a special focus on the synthesis, characterization and integration of these materials in smart windows and other architectural elements such as building integrated dye-sensitized solar panels. Different luminophores have been used to realize semitransparent and colorless photovoltaic windows to convert the energy-passive façades of urban buildings into effective energy and, at the same time, promoting building’s visual and thermal comfort. Here we used inorganic dyes with rare-earth elements such as Eu3+ and Nd3+/Yb3+ lanthanide couple to energy incident photons are not absorbed, whereas the excess energy carried by photons with energy higher than the bandgap causes thermalization of the charge carriers [4]. To overcome this limitation and enhance the energy conversion efficiency, one can resort to downshifting or downconversion mechanisms and modify the incident solar spectrum. With the advances on the development of LSCs, different types of luminescent species have been used with this purpose. This paper reports the development of multifunctional coatings to enhance the performance of such systems.