Photoinduced high-quality ultrathin SiO2 film from hybrid nanosheet at room temperature.
ABSTRACT The paper describes a flexible approach to building up high-quality ultrathin SiO2 films under deep UV light irradiation at room temperature. The ultrathin hybrid nanosheet possessing polyoctahedral silsesquioxane (POSS) has been designed to prepare densely packed ultrathin POSS films by the Langmuir-Blodgett (LB) technique. The LB technique enables POSS to have a multilayered structure with nanoscale precision. The films' hardness and modulus changed considerably from 0.1 and 2.6 GPa to 1.7 and 32.2 GPa, respectively, after deep UV light irradiation. Subsequent FTIR measurements revealed that the organic components were removed completely and that the POSS cage structure turned to an Si-O-Si network structure. X-ray photon spectroscopy also confirmed high-quality SiO2 formation with no suboxides.
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ABSTRACT: Ternary oxide Zn3V2O8 films was successfully formed on glass substrates only by means of vacuum ultraviolet irradiation to the spin-coated metal–organic solutions. From Fourier transform infrared spectroscopy measurements, we confirmed that the crystal growth proceeded at metal–organic bond cleavage under VUV irradiation. The crystalline size of the obtained materials was estimated to be 1.5–2.5 nm. The prepared Zn3V2O8 films clearly showed yellow luminescence, corresponding to a charge transfer transition in the VO4 tetrahedra.Applied Physics A 01/2010; 98(4):885-888. · 1.69 Impact Factor
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ABSTRACT: The fabrication of thin oxide films at low temperatures using simple processes has been a significant challenge associated with expanding the potential applications of these materials. Recent developments have demonstrated that the photo-assisted chemical solution deposition (PACSD) process offers a promising means of solving these difficulties, allowing high volume, on-demand production of variable sample sizes using an advantageous wet process. A better understanding of the crystal growth phenomena associated with this process, however, is required to enable various oxide thin films to be prepared using this new concept. Under pulsed ultraviolet (UV) laser irradiation, crystal growth has been confirmed to proceed by near-instantaneous photothermal heating and photochemical effects at the reaction interface. Vacuum UV lamp irradiation is also a useful means of generating oxide nuclei, since it results in effective chemical bond cleavage and simultaneously produces reactive oxidant (O3/O((1)D)) species. In this review, the nucleation and growth mechanisms which occur during the PACSD process are introduced and discussed and we examine the future possible applications of this process.Chemical Society Reviews 08/2013; · 30.43 Impact Factor
Article: Porphyrin-POSS molecular hybrids.[Show abstract] [Hide abstract]
ABSTRACT: Porphyrin-POSS hybrid: Porphyrin-POSS molecular hybrid composites (see scheme; POSS = polyhedral oligomeric silsesquioxanes) were synthesized and structurally characterized, allowing the realization of truly homogenous dispersion of basic functional building blocks between organic and inorganic components at the molecular level. These materials allow the optimization of aggregation/association behavior and thus the functional optical properties of the porphyrinato zinc compounds.Chemistry - A European Journal 09/2013; 19(38):12613-8. · 5.93 Impact Factor