Chetan J. Bhongale; Rahul Chaudhari; Yashwant Pandit
Abstract
The applications of nano-dispersed organic conjugated active compounds or materials as well as current research is concerned mainly with optimization and control of the optical properties, by particle size and supramolecular structure of the particles. The aromatic macromolecules consisting of conjugated ...
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The applications of nano-dispersed organic conjugated active compounds or materials as well as current research is concerned mainly with optimization and control of the optical properties, by particle size and supramolecular structure of the particles. The aromatic macromolecules consisting of conjugated rigid rod segment and hydrophilic flexible chain as coil in aqueous solution can aggregate into a variety of supramolecular structures through mutual interaction between aromatic rod and hydrophilic chains of molecules and water. Here we report the synthesis of newer oligo phenylene vinylene (OPV) based rod-coil molecules with varying chain-length polyethylene oxide (PEO) repeating units (n = 8, 17, 45). Formation and photophysical properties of their nanostructures in water are studied comparatively. The nanostructures evolution of these molecules is observed with simple reprecipitation method. The stable nanostructures were formed without addition of any surfactants. The fabricated nanostructures ultimately give the materials with ‘controlled’ aggregation induced enhanced photophysical properties. The self-assembly of such OPV type rod molecules in water without adding any surfactants, therefore, can provide a strategy for the construction of well-defined and stable nanostructures with certain chemical functionalities and physical properties as advanced materials for photonic, electronic and biological applications. Copyright © VBRI Press.

Yashwant Pandit; G. T. Harini; Deepa Landage; Chetan J. Bhongale
Abstract
The formation of mesoscopic titania is done by templated mechanism in which the films are prepared by co-assembly of titania precursor species and complexing agent acetyl acetone (acac) and an amphiphilic structure-directing agent, Pluronic F127 (a triblock copolymer). Thinner films of titania having ...
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The formation of mesoscopic titania is done by templated mechanism in which the films are prepared by co-assembly of titania precursor species and complexing agent acetyl acetone (acac) and an amphiphilic structure-directing agent, Pluronic F127 (a triblock copolymer). Thinner films of titania having well organized mesoscopic structure were prepared by doctor-blading method. These films were characterized by SEM, TEM, XRD, etc. UV-Vis absorption studies showed good dye intake in very thin mesoscopic titania layers. Prototype photovoltaic device fabricated utilizing the mesoscopic titania films showed reasonable power conversion efficiency and fill factor (FF). The device with mesoscopic TiO2 layer with thickness as low as 300 nm gave solar cell efficiency 0.31% and FF of 50.2%. This proves the utility of very thin layer of mesoscopic titania fabricated by doctor-blading technique. Such a thin layer may be useful in perovskite solar cells as well. Application of versatile dye molecules, polymers with suitable anchoring functionality could lead to desired high-performance photovoltaic devices.
