Sensitization of nanocrystalline TiO2 with 3,4,9,10-perylene tetracarboxylic acid

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 16; no. 7; p. 1
• Main Authors: Calandra, P., Fazio, E., Neri, F., Leone, N., Turco Liveri, V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2014; Springer; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Inorganic Chemistry; Lasers; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials Science; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanotechnology; Optical Devices; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optics; Photonics; Physical Chemistry; Physics; Research Paper; Solid surfaces and solid-solid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Titania nanoparticles; Z-scan method; Optical limiting; Dye sensitization; Absorption and fluorescence spectroscopies; Fluorescence spectroscopy; Dye-sensitized solar cell; Dyes; Fluorescence; Nanostructures; Relaxation time; Z scan; Nanoparticles; Absorption band; Optical properties; Perylene; Alcoholic solution; Absorption spectra; Nonlinear optics; Nanocrystal; Data analysis; Ethanol; Carboxylic acids; Steady state; Time resolved spectra; Nonlinear optical susceptibility; Solid state; Time resolution; Experimental result; Composite materials; Adsorption; Ultraviolet visible spectrum; Non linear effect; Nanostructured materials
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-014-2495-y

Optical properties of 3,4,9,10-perylene tetracarboxylic acid (PTCA) in the presence of nanocrystalline TiO 2 (nominal diameter 15 nm) have been investigated in ethanol solution and in the solid state by UV–Vis absorption spectroscopy and steady-state and time-resolved fluorescence. Experimental results show that, in ethanol, the presence of TiO 2 nanoparticles causes significant changes in the typical absorption and fluorescence bands of PTCA and in the fluorescence relaxation time. Similar effects are also detected in solid samples, obtained by electrospray deposition technique. The nonlinear optical properties of the PTCA–TiO 2 in ethanol solutions were investigated using the single-beam Z-scan techniques at 532 nm. It was found that, at high TiO 2 nanoparticles content, PTCA exhibits a reverse saturable absorption with significant nonlinear absorption and intensity-dependent negative nonlinear refractive coefficient, indicating self-defocusing behaviour. The third-order nonlinear susceptibility and optical limiting threshold were also determined. Data analysis leads consistently to attribute the observed behaviours to chemical adsorption of PTCA to the TiO 2 surface both in liquid and solid samples. Potentialities of these novel luminescent nanostructured composites as components of dye-sensitized solar cells or components where the nonlinear optical behaviour is requested have been highlighted.