Aggregation induced emission enhancement (AIEE) of fluorenyl appended Schiff base : A turn on fluorescent probe for Al³⁺, and its photovoltaic effect

Fluorenyl-diformyl phenol Schiff (HL) base is spectroscopically characterized and demonstrates aggregation induced emission enhancement (AIEE) upon addition of water to THF solution. Maximum intensity is observed at 90% of water addition at 570 nm. Al³⁺ induced turn-on fluorescence enhancement is observed at 600 nm and the limit of optical detection (LOD) is 6.22x10⁻⁹ M. Isolation of Al(III)-complex and mass spectral measurement shows the formation of phenoxo-bridged dinuclear complex. Applicability for DSSC device fabrication of probe shows photovoltaic efficiency 0.021%. DFT computation of optimized geometry of HL has been used to explain the spectral and photovoltaic activity.