The dielectric breakdown (BD) kinetics of praseodymium thin films has been determined by comparis... more The dielectric breakdown (BD) kinetics of praseodymium thin films has been determined by comparison between current-voltage measurements on large-area (up to 78.54 mum2) metal-oxide-semiconductor structures and conductive-atomic force microscopy (C-AFM). C-AFM clearly images the weak BD single spots under constant voltage stresses. The stress time on the single C-AFM tip dot was varied from 2.5×10-3 to 8×10-2 s. The density
P. Fiorenza, 1,a R. Lo Nigro, 2,b V. Raineri, 1,c S. Lombardo, 1,d RG Toro, 2,e G. ... 1CNR-IMM ... more P. Fiorenza, 1,a R. Lo Nigro, 2,b V. Raineri, 1,c S. Lombardo, 1,d RG Toro, 2,e G. ... 1CNR-IMM Stradale Primosole, 50 95121 Catania, Italy 1Dipartimento di Scienze Chimiche, Università di Catania Viale Andrea Doria 6 95125 Catania, ... Italy. apatrick.fiorenza@imm.cnr.it; ...
... Roberta G. Toro ... Figure 7 shows the experimental and calculated spectra of the ellipsometr... more ... Roberta G. Toro ... Figure 7 shows the experimental and calculated spectra of the ellipsometric variables (I s = sin(2ψ) sin(2Δ) and I c = sin(2ψ) cos(2Δ)) measured at various incidence angles (55, 60, and 65°) for the 100 CeO 2 oriented film grown on TiO 2 . The same multiple ...
ABSTRACT We have investigated the spectroscopic behavior of three different sensitizers adsorbed ... more ABSTRACT We have investigated the spectroscopic behavior of three different sensitizers adsorbed onto titania thin films in order to gain information both on the electron transfer process from dye to titania and on the anchorage of the chromophore onto the semiconductor. We have examined by UV-Vis and fluorescence spectroscopy the widely used ruthenium complex cis-di(thiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) (N719), the more recently developed organic molecular 3-(5-(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D5), and a push-pull zinc phthalocyanine sensitizer (ZnPc). Three type of titania films with different morphology, characterized by SEM and FT-IR measurement, were considered: a mesoporous transparent film deposited by spin-coating (TiMS), a semiopaque film deposited by doctor-blade from mesoporous titania (TiMS_DB) and a semiopaque film deposited by doctor-blade form commercial P25 titania (P25_DB). The use of TiMS is responsible for the adsorption of a higher amount of dye since the mesoporous structure allows increasing the interfacial area between dye and titania. Moreover, the fluorescence emission peak is weaker when the sensitizers are adsorbed onto TiMS. These findings suggest that mesostructured films could be considered the most promising substrates to realize photoanodes with a fast electron transfer process.
Unconventional nanopatterning methods are emerging as powerful tools for the development of contr... more Unconventional nanopatterning methods are emerging as powerful tools for the development of controlled shapes and ordered morphology of nanostructured materials with novel properties and tailorable functions. Here, we report a simple yet straightforward and efficient approach for patterning through unconventional dewetting that involves surface tension driven process. Using this innovative approach, we have successfully demonstrated to be able to prepare surface micro-patterns over large areas deposited through Eu(3+):TiO2 nanoparticles providing rational control over the local nucleation of nanoparticles. Remarkably, these features could be addressed by polar or apolar solvents, suggesting potential applications in bottom-up nanodevices. This paper represents the first such attempt to create an inorganic materials non-lithographic template for the directed deposition of Eu(3+):TiO2 or related metal oxides. The technique, which is driven by the unique chemical properties and geometrical layout of the underlying patterned micrometer-sized templates, enables the construction of micro- and nano-structuration of dispersed inorganic functional materials suitable for electrooptical and photonic applications.
Praseodymium oxide (Pr2O3) thin films have been deposited on Si(100) substrates by metalorganic c... more Praseodymium oxide (Pr2O3) thin films have been deposited on Si(100) substrates by metalorganic chemical vapor deposition using praseodymium tris-2,2,6,6-tetramethyl-3,5-heptandionate as source material. Film structural, morphological, and compositional characterizations have been carried out. Dielectric properties have been studied as well by capacitance-voltage and current-voltage measurements on metal-oxide-semiconductor capacitors of several areas. The Pr2O3 films have shown a dielectric constant ε=23-25 and a leakage current density of 8.8×10-8 A/cm2 at +1 V.
Calcium copper titanate, CaCu3Ti4O12 (CCTO), thin films have been fabricated by Metal Organic Che... more Calcium copper titanate, CaCu3Ti4O12 (CCTO), thin films have been fabricated by Metal Organic Chemical Vapor Deposition on silicon substrates buffered with two different low-k interlayers, namely SiO2 and Si3N4. Depositions have been carried out from a molten ...
A novel approach based on a molten multicomponent precursor source has been applied for the MOCVD... more A novel approach based on a molten multicomponent precursor source has been applied for the MOCVD fabrication of high-quality CaCu(3)Ti(4)O(12) (CCTO) thin films on various substrates. The adopted in situ strategy involves a molten mixture consisting of Ca(hfa)(2).tetraglyme, Ti(tmhd)(2)(O-iPr)(2), and Cu(tmhd)(2) [Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = 2,5,8,11,14-pentaoxapentadecane; Htmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = isopropoxide] precursors. Film structural and morphological characterizations have been carried out by several techniques [X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM)], and in particular the energy filtered TEM mapping and X-ray energy dispersive (EDX) analysis in TEM mode provided a suitable correlation between nanostructural properties of CCTO films and deposition conditions and/or the substrate nature. Correlation between the nanostructure and optical/dielectric properties has been investigated exploiting spectroscopic ellipsometry.
... Raffaella Lo Nigroa, Roberta G. Torob, Graziella Malandrino*b and Ignazio L. Fragalà*b. a IMM... more ... Raffaella Lo Nigroa, Roberta G. Torob, Graziella Malandrino*b and Ignazio L. Fragalà*b. a IMM, sezione di Catania, CNR, Stradale Primosole n 50 ... Isothermogravimetric analyses were performed by using a Mettler Toledo TGA/SDTA 851 e in purified nitrogen flow (30 sccm). ...
Complementary metal-oxide-semiconductor large-scale integrated circuits (CMOS LSIs) are the most ... more Complementary metal-oxide-semiconductor large-scale integrated circuits (CMOS LSIs) are the most popular devices for electronics. High-performance devices, require, however, downsizing of components such as metal-oxide-semiconductor field effect transistors (MOSFETs). ...
The possibility to image the local permittivity in giant-dielectrics by scanning probe microscopy... more The possibility to image the local permittivity in giant-dielectrics by scanning probe microscopy was demonstrated. In particular, the microstructure and the dielectric properties of (CCTO) films grown on (001) substrates were studied. CCTO amorphous layers obtained by metal-...
The dielectric breakdown (BD) kinetics of praseodymium thin films has been determined by comparis... more The dielectric breakdown (BD) kinetics of praseodymium thin films has been determined by comparison between current-voltage measurements on large-area (up to 78.54 mum2) metal-oxide-semiconductor structures and conductive-atomic force microscopy (C-AFM). C-AFM clearly images the weak BD single spots under constant voltage stresses. The stress time on the single C-AFM tip dot was varied from 2.5×10-3 to 8×10-2 s. The density
P. Fiorenza, 1,a R. Lo Nigro, 2,b V. Raineri, 1,c S. Lombardo, 1,d RG Toro, 2,e G. ... 1CNR-IMM ... more P. Fiorenza, 1,a R. Lo Nigro, 2,b V. Raineri, 1,c S. Lombardo, 1,d RG Toro, 2,e G. ... 1CNR-IMM Stradale Primosole, 50 95121 Catania, Italy 1Dipartimento di Scienze Chimiche, Università di Catania Viale Andrea Doria 6 95125 Catania, ... Italy. apatrick.fiorenza@imm.cnr.it; ...
... Roberta G. Toro ... Figure 7 shows the experimental and calculated spectra of the ellipsometr... more ... Roberta G. Toro ... Figure 7 shows the experimental and calculated spectra of the ellipsometric variables (I s = sin(2ψ) sin(2Δ) and I c = sin(2ψ) cos(2Δ)) measured at various incidence angles (55, 60, and 65°) for the 100 CeO 2 oriented film grown on TiO 2 . The same multiple ...
ABSTRACT We have investigated the spectroscopic behavior of three different sensitizers adsorbed ... more ABSTRACT We have investigated the spectroscopic behavior of three different sensitizers adsorbed onto titania thin films in order to gain information both on the electron transfer process from dye to titania and on the anchorage of the chromophore onto the semiconductor. We have examined by UV-Vis and fluorescence spectroscopy the widely used ruthenium complex cis-di(thiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) (N719), the more recently developed organic molecular 3-(5-(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D5), and a push-pull zinc phthalocyanine sensitizer (ZnPc). Three type of titania films with different morphology, characterized by SEM and FT-IR measurement, were considered: a mesoporous transparent film deposited by spin-coating (TiMS), a semiopaque film deposited by doctor-blade from mesoporous titania (TiMS_DB) and a semiopaque film deposited by doctor-blade form commercial P25 titania (P25_DB). The use of TiMS is responsible for the adsorption of a higher amount of dye since the mesoporous structure allows increasing the interfacial area between dye and titania. Moreover, the fluorescence emission peak is weaker when the sensitizers are adsorbed onto TiMS. These findings suggest that mesostructured films could be considered the most promising substrates to realize photoanodes with a fast electron transfer process.
Unconventional nanopatterning methods are emerging as powerful tools for the development of contr... more Unconventional nanopatterning methods are emerging as powerful tools for the development of controlled shapes and ordered morphology of nanostructured materials with novel properties and tailorable functions. Here, we report a simple yet straightforward and efficient approach for patterning through unconventional dewetting that involves surface tension driven process. Using this innovative approach, we have successfully demonstrated to be able to prepare surface micro-patterns over large areas deposited through Eu(3+):TiO2 nanoparticles providing rational control over the local nucleation of nanoparticles. Remarkably, these features could be addressed by polar or apolar solvents, suggesting potential applications in bottom-up nanodevices. This paper represents the first such attempt to create an inorganic materials non-lithographic template for the directed deposition of Eu(3+):TiO2 or related metal oxides. The technique, which is driven by the unique chemical properties and geometrical layout of the underlying patterned micrometer-sized templates, enables the construction of micro- and nano-structuration of dispersed inorganic functional materials suitable for electrooptical and photonic applications.
Praseodymium oxide (Pr2O3) thin films have been deposited on Si(100) substrates by metalorganic c... more Praseodymium oxide (Pr2O3) thin films have been deposited on Si(100) substrates by metalorganic chemical vapor deposition using praseodymium tris-2,2,6,6-tetramethyl-3,5-heptandionate as source material. Film structural, morphological, and compositional characterizations have been carried out. Dielectric properties have been studied as well by capacitance-voltage and current-voltage measurements on metal-oxide-semiconductor capacitors of several areas. The Pr2O3 films have shown a dielectric constant ε=23-25 and a leakage current density of 8.8×10-8 A/cm2 at +1 V.
Calcium copper titanate, CaCu3Ti4O12 (CCTO), thin films have been fabricated by Metal Organic Che... more Calcium copper titanate, CaCu3Ti4O12 (CCTO), thin films have been fabricated by Metal Organic Chemical Vapor Deposition on silicon substrates buffered with two different low-k interlayers, namely SiO2 and Si3N4. Depositions have been carried out from a molten ...
A novel approach based on a molten multicomponent precursor source has been applied for the MOCVD... more A novel approach based on a molten multicomponent precursor source has been applied for the MOCVD fabrication of high-quality CaCu(3)Ti(4)O(12) (CCTO) thin films on various substrates. The adopted in situ strategy involves a molten mixture consisting of Ca(hfa)(2).tetraglyme, Ti(tmhd)(2)(O-iPr)(2), and Cu(tmhd)(2) [Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = 2,5,8,11,14-pentaoxapentadecane; Htmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = isopropoxide] precursors. Film structural and morphological characterizations have been carried out by several techniques [X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM)], and in particular the energy filtered TEM mapping and X-ray energy dispersive (EDX) analysis in TEM mode provided a suitable correlation between nanostructural properties of CCTO films and deposition conditions and/or the substrate nature. Correlation between the nanostructure and optical/dielectric properties has been investigated exploiting spectroscopic ellipsometry.
... Raffaella Lo Nigroa, Roberta G. Torob, Graziella Malandrino*b and Ignazio L. Fragalà*b. a IMM... more ... Raffaella Lo Nigroa, Roberta G. Torob, Graziella Malandrino*b and Ignazio L. Fragalà*b. a IMM, sezione di Catania, CNR, Stradale Primosole n 50 ... Isothermogravimetric analyses were performed by using a Mettler Toledo TGA/SDTA 851 e in purified nitrogen flow (30 sccm). ...
Complementary metal-oxide-semiconductor large-scale integrated circuits (CMOS LSIs) are the most ... more Complementary metal-oxide-semiconductor large-scale integrated circuits (CMOS LSIs) are the most popular devices for electronics. High-performance devices, require, however, downsizing of components such as metal-oxide-semiconductor field effect transistors (MOSFETs). ...
The possibility to image the local permittivity in giant-dielectrics by scanning probe microscopy... more The possibility to image the local permittivity in giant-dielectrics by scanning probe microscopy was demonstrated. In particular, the microstructure and the dielectric properties of (CCTO) films grown on (001) substrates were studied. CCTO amorphous layers obtained by metal-...
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