Universal electrolyte for DSSC οperation under both simulated solar and indoor fluorescent lighting

Abstract

A universal I−/I3− redox electrolyte solution for well performing DSSCs under both indoor and outdoor lighting conditions, is presented and characterized. Electrolyte attributes, including color and mass transport properties, were tailored and a good synergy between triiodide content, organic solvent mixture and additives in the electrolyte has been achieved, allowing DSSC adaptability under different lighting types and illumination intensities. The optical and redox properties were evaluated and the electrolyte was tested in DSSCs under different illumination conditions: simulated solar light (from 0.1 to 1 sun) and indoor light (from 100 to 1000 lux). Under indoor lighting, the electrolyte leads to power conversion efficiency (PCE) values close to the ones for the best performing iodide-based devices reported in the literature. Moreover, significantly superior performance, along with a constantly high fill factor were achieved under 100 mW/cm2 simulated solar light, paving the way for the development of low cost DSSCs with good ''pan-illumination'' performance, independently of the lighting conditions.