Intelligent Design and Experimental Application of Spectral Splitting and Selective Surfaces for Sunlight

This project aims to develop advanced materials solutions for next generation solar energy harvesting systems: Concentrated Solar Thermal (CST) technologies, generating heat, can be combined with Photovoltaic (PV), generating low-cost electricity, in compact hybrid PV-CST systems where PV cells replace mirrors on the concentrators. This type of system will maintain current solar electricity production costs while adding simultaneous heat generation for various end users (residential, commercial, industrial), including the option of thermal storage to address solar intermittency and enable on-demand electricity and heat production. For this application, innovative spectrally selective surfaces are necessary, especially “PV mirrors” splitting the solar spectrum, transparent towards the underlying PV cells and reflective towards the thermal absorbers placed at the focus of the concentrators. Highly absorbing, low emissive solar selective coatings adapted to the truncated solar spectrum are also needed for the thermal absorbers.In this project, these selective surface properties will be achieved by developing efficient multilayered thin film architectures. The latter will first be designed by numerical simulations using advanced optimization methods, using in-house SolPOC open source code. Efforts will be put on reducing environmental impacts, by selecting sustainable materials and minimizing development time and cost through extensive optical simulation. The best solutions will be synthesized by vacuum sputtering deposition to validate the coatings feasibility. Thermo-optical characterizations will validate their performance. Comparisons with simulated optical behavior will validate the design methods, providing a reliable and free tool for developing optical surfaces and solar, accessible to all. Doing thus, the researcher will acquire new experimental skills and increase his employability, while applying his own extensive expertise to fulfill our goals.