Renato Bozio - Academia.edu (original) (raw)
Papers by Renato Bozio
Nano research & applications, May 10, 2018
RSC Advances, 2017
Oxidation effects on SERS response of Ag nanoprism arrays are interpreted by FEM simulations of t... more Oxidation effects on SERS response of Ag nanoprism arrays are interpreted by FEM simulations of the local-field distribution around the nanoprisms.
Journal of Sol-Gel Science and Technology
Journal of Sol-Gel Science and Technology
SPIE Proceedings, 2003
ABSTRACT A novel scheme for implementing the joint exploitation of different, somehow complementa... more ABSTRACT A novel scheme for implementing the joint exploitation of different, somehow complementary mechanisms of nonlinear transmission in an optical limiting device is proposed. As active materials we have chosen the fullerene derivative FULP, as a reverse saturable absorber, and a new heterocyclic quadrupolar dye, PEPEP, with highly efficient multiphoton absorption for nanosecond pulses. The nonlinear absorption properties of PEPEP in solution are extensively investigated for both femtosecond and nanosecond ...
Light Manipulating Organic Materials and Devices, 2014
In the attempt to improve optical limiting of cw lasers by exploiting the thermo-optic effect exh... more In the attempt to improve optical limiting of cw lasers by exploiting the thermo-optic effect exhibited by gold nanostructures, we investigated two coupled systems consisting of either gold nanoparticles (AuNPs) or gold-silica core-shell (AuNSs), both functionalized with a thiolated-fulleropyrrolidine (C60Py). We measured the optical limiting behavior under cw illumination at 514 and 647 nm, resonant with the surface plasmon resonance at around 520 of AuNPs and at 650 nm of AuNSs, respectively. Temporal response analysis shows the variation of transmitted irradiance in a 300 milliseconds time interval, corresponding to the blinking time of the human eye. Comparing the present results we those previously obtained for AuNPs1 we demonstrate an improvement of the response of functionalized nanoparticles (AuNPs- C60Py) with respect to bare AuNPs.
The Journal of Physical Chemistry C, 2010
In this paper, we have investigated the properties of a composite SiO2− TiO2/TiO2 nanoparticle sy... more In this paper, we have investigated the properties of a composite SiO2− TiO2/TiO2 nanoparticle system. Hybrid films have been prepared using a sol− gel process, starting from tetraisopropoxy titanate and 3-glycidoxipropyltrimethoxysilane as precursors and performing the synthesis at room temperature. The spin-coated films have been thoroughly characterized with UV− vis and FT-IR spectroscopies, TEM analysis, profilometry, and ellipsometry to evaluate their physical and structural properties. Particular attention has ...
The Journal of Physical Chemistry C, 2011
The Journal of Physical Chemistry A, 2006
This paper presents the synthesis and two photon-induced absorption (TPA) properties of a functio... more This paper presents the synthesis and two photon-induced absorption (TPA) properties of a functionalized distyrylbenzene (DSB) 1 containing a tetra-azacyclododecane (cyclen) receptor for Zn(II). The influence of Zn(II) on one- and two-photon absorption characteristics of 1 has been investigated in dimethyl sulfoxide. The experiments show that the TPA action spectrum of uncomplexed 1, at 750 nm employing nanosecond-long excitation pulses, is 5 times more intense than that of the complexed form. This moderate contrast between the bound and unbound species confirms, however, the potential of this design scheme for the development of molecular structures with enhanced sensitivity and contrast to be used as Zn(II) sensors through TPA-induced fluorescence microscopy.
Synthetic Metals, 2001
Résumé/Abstract We report on the synthesis and characterization of a novel series of heterocycle-... more Résumé/Abstract We report on the synthesis and characterization of a novel series of heterocycle-based chromophores for third order non-linear optics (NLO), showing enhanced two-photon absorption activity and frequency-upconverted lasing efficiency. The parent compound is a push-pull system where a pyridinium ion acts as acceptor group and N-methylpyrrole as a donor. Its efficiency in the two-photon-pumped lasing conversion from 800 to 543 nm is one of the highest ever reported. We show here the role of the position ...
Nanoscale, 2011
We report a facile production of an up-converted surface-emitting DFB laser, performed by exploit... more We report a facile production of an up-converted surface-emitting DFB laser, performed by exploiting the versatility of sol-gel chemistry, the intriguing properties of well designed graded CdSe-CdS-Cd(0.5)Zn(0.5)S-ZnS colloidal quantum dots, and the scalability of nanoimprinting. Our laser prototype operates in the visible region following efficient optical pumping by either direct one-photon excitation or through the up-conversion of near infrared (NIR) light. By achieving cavity mode Q-factors in excess of 650 and retaining high lasing stabilities in air, this work highlights the feasibility of creating integrated lasing devices through solution based methods.
Journal of the American Chemical Society, 2003
We report, for the first time, the organic functionalization of carbon onions. The functionalizat... more We report, for the first time, the organic functionalization of carbon onions. The functionalization was achieved via 1,3-dipolar cycloaddition of azomethine ylides to a mixture of amorphous carbon and concentric fullerenes. Once functionalized, the onions become soluble in organic solvents and it is possible to purify them from the rest of carbon. Their nonlinear optical properties have been studied in solution for application as broadband optical limiters. It was found that the functionalized onions are an example of soluble material that functions equally well in both the visible and the NIR regions.
Journal of Non-Crystalline Solids, 2000
Chemistry - A European Journal, 1999
Homogeneous fullerene-containing glasses, obtained by solgel processing, exhibit very promising ... more Homogeneous fullerene-containing glasses, obtained by solgel processing, exhibit very promising optical-limiting properties (see picture). The chemical grafting of the fullerene derivatives to the silica matrix guarantees nearly perfect dispersions of the organic dye in the polymer. The ...
Chemistry of Materials, 2008
Chemical Communications, 2003
Carbon, 2000
Non linear optical properties of pyrrolidino-fullerenes in sol–gel matrix have been investigated ... more Non linear optical properties of pyrrolidino-fullerenes in sol–gel matrix have been investigated for Optical Limiting (OL) applications. The fullerene functionalization increases the solubility in polar solvent and allows the preparation of solid materials via sol–gel method. It also extends the absorption of fullerenes to the red spectral region, where the maximum of the triplet to triplet absorption spectrum is located
Nano research & applications, May 10, 2018
RSC Advances, 2017
Oxidation effects on SERS response of Ag nanoprism arrays are interpreted by FEM simulations of t... more Oxidation effects on SERS response of Ag nanoprism arrays are interpreted by FEM simulations of the local-field distribution around the nanoprisms.
Journal of Sol-Gel Science and Technology
Journal of Sol-Gel Science and Technology
SPIE Proceedings, 2003
ABSTRACT A novel scheme for implementing the joint exploitation of different, somehow complementa... more ABSTRACT A novel scheme for implementing the joint exploitation of different, somehow complementary mechanisms of nonlinear transmission in an optical limiting device is proposed. As active materials we have chosen the fullerene derivative FULP, as a reverse saturable absorber, and a new heterocyclic quadrupolar dye, PEPEP, with highly efficient multiphoton absorption for nanosecond pulses. The nonlinear absorption properties of PEPEP in solution are extensively investigated for both femtosecond and nanosecond ...
Light Manipulating Organic Materials and Devices, 2014
In the attempt to improve optical limiting of cw lasers by exploiting the thermo-optic effect exh... more In the attempt to improve optical limiting of cw lasers by exploiting the thermo-optic effect exhibited by gold nanostructures, we investigated two coupled systems consisting of either gold nanoparticles (AuNPs) or gold-silica core-shell (AuNSs), both functionalized with a thiolated-fulleropyrrolidine (C60Py). We measured the optical limiting behavior under cw illumination at 514 and 647 nm, resonant with the surface plasmon resonance at around 520 of AuNPs and at 650 nm of AuNSs, respectively. Temporal response analysis shows the variation of transmitted irradiance in a 300 milliseconds time interval, corresponding to the blinking time of the human eye. Comparing the present results we those previously obtained for AuNPs1 we demonstrate an improvement of the response of functionalized nanoparticles (AuNPs- C60Py) with respect to bare AuNPs.
The Journal of Physical Chemistry C, 2010
In this paper, we have investigated the properties of a composite SiO2− TiO2/TiO2 nanoparticle sy... more In this paper, we have investigated the properties of a composite SiO2− TiO2/TiO2 nanoparticle system. Hybrid films have been prepared using a sol− gel process, starting from tetraisopropoxy titanate and 3-glycidoxipropyltrimethoxysilane as precursors and performing the synthesis at room temperature. The spin-coated films have been thoroughly characterized with UV− vis and FT-IR spectroscopies, TEM analysis, profilometry, and ellipsometry to evaluate their physical and structural properties. Particular attention has ...
The Journal of Physical Chemistry C, 2011
The Journal of Physical Chemistry A, 2006
This paper presents the synthesis and two photon-induced absorption (TPA) properties of a functio... more This paper presents the synthesis and two photon-induced absorption (TPA) properties of a functionalized distyrylbenzene (DSB) 1 containing a tetra-azacyclododecane (cyclen) receptor for Zn(II). The influence of Zn(II) on one- and two-photon absorption characteristics of 1 has been investigated in dimethyl sulfoxide. The experiments show that the TPA action spectrum of uncomplexed 1, at 750 nm employing nanosecond-long excitation pulses, is 5 times more intense than that of the complexed form. This moderate contrast between the bound and unbound species confirms, however, the potential of this design scheme for the development of molecular structures with enhanced sensitivity and contrast to be used as Zn(II) sensors through TPA-induced fluorescence microscopy.
Synthetic Metals, 2001
Résumé/Abstract We report on the synthesis and characterization of a novel series of heterocycle-... more Résumé/Abstract We report on the synthesis and characterization of a novel series of heterocycle-based chromophores for third order non-linear optics (NLO), showing enhanced two-photon absorption activity and frequency-upconverted lasing efficiency. The parent compound is a push-pull system where a pyridinium ion acts as acceptor group and N-methylpyrrole as a donor. Its efficiency in the two-photon-pumped lasing conversion from 800 to 543 nm is one of the highest ever reported. We show here the role of the position ...
Nanoscale, 2011
We report a facile production of an up-converted surface-emitting DFB laser, performed by exploit... more We report a facile production of an up-converted surface-emitting DFB laser, performed by exploiting the versatility of sol-gel chemistry, the intriguing properties of well designed graded CdSe-CdS-Cd(0.5)Zn(0.5)S-ZnS colloidal quantum dots, and the scalability of nanoimprinting. Our laser prototype operates in the visible region following efficient optical pumping by either direct one-photon excitation or through the up-conversion of near infrared (NIR) light. By achieving cavity mode Q-factors in excess of 650 and retaining high lasing stabilities in air, this work highlights the feasibility of creating integrated lasing devices through solution based methods.
Journal of the American Chemical Society, 2003
We report, for the first time, the organic functionalization of carbon onions. The functionalizat... more We report, for the first time, the organic functionalization of carbon onions. The functionalization was achieved via 1,3-dipolar cycloaddition of azomethine ylides to a mixture of amorphous carbon and concentric fullerenes. Once functionalized, the onions become soluble in organic solvents and it is possible to purify them from the rest of carbon. Their nonlinear optical properties have been studied in solution for application as broadband optical limiters. It was found that the functionalized onions are an example of soluble material that functions equally well in both the visible and the NIR regions.
Journal of Non-Crystalline Solids, 2000
Chemistry - A European Journal, 1999
Homogeneous fullerene-containing glasses, obtained by solgel processing, exhibit very promising ... more Homogeneous fullerene-containing glasses, obtained by solgel processing, exhibit very promising optical-limiting properties (see picture). The chemical grafting of the fullerene derivatives to the silica matrix guarantees nearly perfect dispersions of the organic dye in the polymer. The ...
Chemistry of Materials, 2008
Chemical Communications, 2003
Carbon, 2000
Non linear optical properties of pyrrolidino-fullerenes in sol–gel matrix have been investigated ... more Non linear optical properties of pyrrolidino-fullerenes in sol–gel matrix have been investigated for Optical Limiting (OL) applications. The fullerene functionalization increases the solubility in polar solvent and allows the preparation of solid materials via sol–gel method. It also extends the absorption of fullerenes to the red spectral region, where the maximum of the triplet to triplet absorption spectrum is located