A multi-functional transparent photonic-redox system for translucent blue dye-sensitized solar cells: Enhanced UV blocking, light utilization efficiency, color fidelity and near-unity bifaciality

Since colored architectural glass has become available on market, blue glass-chunks have been employed in buildings to improve aesthetics and functionality above clear glass. Simultaneously, new photovoltaic technologies with increased engineering capabilities have opened the way for the development of new building-integrated photovoltaic (BIPV) systems, enabling glass-façades to produce electricity for full/partial coverage of the escalating energy needs. The present work introduces a multi-functional material designed to increase the light utilization efficiency (LUE) and bifaciality of blue semi-transparent dye-sensitized solar cells, while concurrently reducing the UV-light permeability through the system and balancing color rendering. More specifically, a transparent-to-visible-light electrolyte with an integrated down-shifting material in its composition is employed to absorb UV-light and convert it into visible-light, able to be exploited effectively by a blue molecular-sensitizer. To this end, inkjet-printed photovoltaics up to 100 cm 2 mini-module level demonstrated at 55% human perception of transmittance up to 1.8% LUE (∼85% quantum utilization efficiency) and >80% bifaciality under all-weather irradiation conditions, while the UV-light permeability through the transparent electrolyte system decreased ∼65%. These combined performance metrics reshape the landscape in translucent blue-colored BIPVs, demonstrating that spectral engineering in wavelength-selective solar energy systems unlocks sustainability potential through intelligent light management for new/niche applications.