Extremely large electro-optic effect of TPPS J-aggregates in the PVA or PVP polymer matrix and aqueous solution

Abstract

The molecules of tetra-phenyl porphyrin tetra-sulfonic acid (TPPS) form a J-aggregate via self-organization in aqueous solution. The J-aggregates formed in an aqueous solution with added hydrochloric acid were dispersed in PVP polymer and subjected to electric field modulation spectroscopy. The observed difference in the static polarizability Δα_p between the excited and ground states in the TPPS J-aggregates reached a value 2.66 × 10⁴ times and 1.22 × 10⁵ times larger than in the monomer molecules in PVA and PVP polymer matrices, respectively. This large enhancement factor of the electro-optic effect (EOE) may be induced by the higher-order structure of the J-aggregate. The different enhancement factor for each polymer matrix may be introduced by the structural differences between the polymer matrices. Electric field modulation spectroscopy of the J-aggregate in aqueous solution showed an absorbance change of 25% of the magnitude of absorbance peak.