Tris‐Ethynylphenyl‐amine Fluorophores: Synthesis, Characterisation and Test of Performances in Luminescent Solar Concentrators

Abstract Two fluorescent dyes ( CT‐tEPhA =3,3′,3′′‐(nitrilo tris (benzene‐4,1‐diyl)) tris (1‐(thiophen‐2‐yl)prop‐2‐yn‐1‐one and T‐tEPhA =tris(4‐(thiophen‐2‐ylethynyl)phenyl)amine) have been synthesised and characterised in different solvents and in a poly(methyl methacrylate) (PMMA) matrix. In both cases, relatively high Stokes shifts (SS) and quantum yields (QY) have been displayed. Notably, CT‐tEPhA based on a mild electron‐attracting carbonyl group coupled with the electron‐donating amino‐centre, shows superior light emitting properties (higher SS, red‐shifted emission, QY > 40%) suggesting application in light harvesting systems. Photocurrent measurements of CT‐tEPhA /PMMA films yield a maximum optical efficiency of 6.32% that is greater than that of fluorophores with same emission window and comparable to that of red‐emitting ones. This efficiency might be improved by extending the push‐pull character of CT‐tEPhA to cover the maximum efficiency of the Si‐based PV cell. Nevertheless, these results clearly support the use of push‐pull fluorophores based on the tris (4‐ethynylphenyl)amine core in solar collectors.