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Aqueous solution of meso-tetra(4-sulfonatophenyl)porphine was deposited on electrochemically etched n-Si wafers. The morphology of the hybrid systems was investigated by scanning electron microscope and atomic force microscope techniques. The optical response of the hybrid systems was studied by spectroscopic ellipsometry in the range of 1-5 eV. Particular features in adsorption process were revealed for meso-tetra(4-sulfonatophenyl)porphine deposited on variously chemically treated Si substrates. It was found that porphyrin J-aggregates can be intercalated into large pores formed in a bulk n-Si as well as into nanopores of luminescent oxide layer.

Structure and morphology of porphyrin aggregates and influence of temperature, microwave and ultraviolet radiation, and acoustic cavitation on aggregation process were investigated using absorption spectroscopy and atomic force microscopy. In ambient conditions TPPS 4 forms stick-like J-aggregates with length of 0.05-3 µm, width 22-50 nm and height 4-5 nm. Increased temperature or MW and UV radiation does not influence the aggregates. Acoustic cavitation leads to destruction of stick-shaped aggregates and activates the formation of larger molecular complexes.