A fluorene-based material containing triple azacrown ether groups: synthesis, characterization and application in chemosensors and electroluminescent devices

Abstract

We design a novel multifunctional fluorene-based material containing triple azacrown ether (FTC) not only for application in aqueous solution as a chemosensor towards Fe(3+) but also to enhance the electroluminescence of PLEDs using an environmentally stable aluminum cathode. The photo-physical and sensing properties were investigated by absorption and photoluminescence (PL) spectroscopy. The FTC exhibited specific selectivity and high sensitivity toward Fe(3+), with the Stern-Volmer coefficients (Ksv) being 1.59 × 10(5) M(-1) in a solvent mixture of tetrahydrofuran and water (THF-H2O = 9/1, v/v). The FTC maintained high selectivity toward Fe(3+) in the presence of ten interfering metal cations. The HOMO and LUMO levels were estimated to be -5.88 eV and -2.88 eV, respectively. The FTC significantly enhances the emission performance of PLEDs [ITO/PEDOT:PSS/MEH-PPV/EIL/Al] when used as an electron injection layer (EIL), especially in the presence of metal carbonates. Particularly, the device using K2CO3 doped FTC as the electron-injection layer (EIL) exhibited significantly enhanced performance compared to the one without EIL. The performance was significantly enhanced to 11 630 cd m(-2) and 1.47 cd A(-1), respectively, from 230 cd m(-2) and 0.03 cd A(-1) of the non-FTC device. Current results indicate that multifunctional fluorene-based material FTC is a potential candidate for selective detection of Fe(3+) and as an effective electron injection layer to enhance the performance of MEH-PPV.