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Dye-sensitised solar cells (DSSCs) have attracted immense attention in photovoltaics research and development due to the low cost of fabrication, sustainability and use of abundant natural resources. Natural dyes were adapted to DSSCs as a sensitiser but unfortunately proved to have poor efficiency. Herein, we manufactured two organic dyes from yellow and red gambier fruits and treated both dyes with methanol and isopropyl alcohol. The photoanode and photocathode were prepared from TiO2, sensitiser and indium thin dioxide (ITO); and carbon and indium thin dioxide, respectively. An electrolyte was made by mixing potassium iodide and iodine. The doctor blade method was used to add the semiconductor to the surface of the conducting ITO. UV-Vis and FTIR spectroscopic measurements have been performed to determine the absorbance and functional groups in the gambier extracts. From the analysis of UV-Vis and FTIR spectra, and photovoltaic measurements made under solar irradiation, we found that the gambier extracts are dominated by tannin and flavonoids and that dyes using isopropyl alcohol as the solvent have higher efficiency than using methanol, respectively. This indicates that the gambier extracts and solvents might influence the performance of DSSCs., Indonesia Ministry of Research and Technology/National Agency for Research and Innovation; Riset Desentralisasi PDUPT Research Grant

A fiber optic gas sensor with a PMMA fiber whose clad is modified with chemically sensitive nano-crystalline zinc oxide has been developed and investigated to detect acetone, isopropyl alcohol and benzene gases. The spectral characteristics of the sensor were recorded for different concentrations ranging from (0-500 ppm) for these gases both with as-prepared and annealed nanocrystalline ZnO, and the influence of annealing on the gas sensing has been studied.The response time and recovery time were found to be 48 min. and 42 min. respectively for 500 ppm concentration. � 2013 Elsevier Inc. All rights reserved.

We describe the degradation of chlorocarbons (CCl4, C 6H5CH2Cl and CHCl3) in solution at room temperature (27 � 4 �C) by the monolayer-protected silver quantum cluster, Ag9MSA7 (MSA: mercaptosuccinic acid) in the presence of isopropyl alcohol (IPA). The main degradation products were silver chloride and amorphous carbon. Benzyl chloride was less reactive towards clusters than CCl4 and CHCl3. Materials used in the reactions and the reaction products were characterized using several spectroscopic and microscopic tools such as ultraviolet-visible (UV/Vis) absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), energy dispersive analysis of X-rays (EDAX) and scanning electron microscopy (SEM). We have shown that clusters are more efficient for the degradation of halocarbons than the corresponding monolayer-protected nanoparticles (Ag@MSA, particle diameter 15 � 5 nm) at a given time and temperature. The higher reactivity of clusters is attributed to their small size and large surface area. Clusters and nanoparticles were used for reactions in supported (on neutral alumina) and unsupported forms. A possible mechanism for the reaction has been postulated on the basis of experimental results. � 2013 The Royal Society of Chemistry.

The dielectric relaxation study for the hydrogen bonded binary system of polar liquid isopropyl alcohol in non-associated liquids-methyl benzoate and ethyl benzoate has been carried out, using the HP-LF impedance analyzer in static region, Plunger method in microwave frequency region and Abbe's refractometer in optic region, at different temperature and mole fractions. The dielectric parameters viz. static, optic permittivity, excess permittivity, Bruggeman parameter, relaxation time, excess inverse relaxation time and thermodynamic parameters have been obtained. The dielectric parameters show systematic change with temperature and concentrations. Conformational analysis of the formation of hydrogen bond in the binary mixture systems isopropyl alcohol with methyl benzoate and ethyl benzoate is supported by FT-IR. Hamiltonian quantum mechanical calculations such as AM1, PM3 and MNDO optimized converged geometry operation is performed by using Spartan Modeling software for both pure and equi molar systems and thus the FT-IR spectra are obtained and further compared with the experimental values. � 2010 Elsevier B.V. All rights reserved.

Exposure of polymethylmethacrylate (PMMA) during electron beam lithography (EBL) produces small polymer fragments that dissolve rapidly during the development process. The resist dissolution behavior varies greatly depending on the nature of the developer (solvent) and therefore influences the selection of the EBL parameters, such as dose (sensitivity). A molecular scale examination of the development process is necessary to elucidate the resist–developer interaction mechanisms. In this work, the authors investigate the interaction of short PMMA chains (containing up to 10 MMA units) with common developer components methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). For this purpose, the authors conduct molecular dynamics simulations using the Accelrys Materials Studio package. The simulation results were used to characterize the mixtures in the spirit of the Flory–Huggins theory of polymers and also to extract the diffusivities. The authors found that the behavior of PMMA fragments differed considerably in MIBK as compared with IPA. PMMA fragments containing more than three monomers exhibit stronger attractive interaction with MIBK. For all fragment sizes simulated, the diffusivity of PMMA fragments is 60–160% higher in MIBK as well. Similarly, the authors observed differences in the gyration radii. The authors conclude that the kinetic factor seems to be more significant as compared to affinity factor when accounting for differences in exposure sensitivities due to developer selection.Exposure of polymethylmethacrylate (PMMA) during electron beam lithography (EBL) produces small polymer fragments that dissolve rapidly during the development process. The resist dissolution behavior varies greatly depending on the nature of the developer (solvent) and therefore influences the selection of the EBL parameters, such as dose (sensitivity). A molecular scale examination of the development process is necessary to elucidate the resist–developer interaction mechanisms. In this work, the authors investigate the interaction of short PMMA chains (containing up to 10 MMA units) with common developer components methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). For this purpose, the authors conduct molecular dynamics simulations using the Accelrys Materials Studio package. The simulation results were used to characterize the mixtures in the spirit of the Flory–Huggins theory of polymers and also to extract the diffusivities. The authors found that the behavior of PMMA fragments differed consi...

ZEP brand electron beam resists are well-known for their high sensitivity and etch durability. The various performance metrics such as sensitivity, contrast, and resolution of ZEP resist depend strongly on the development process. In this work, we investigate the development of ZEP-520 resist through contrast curves, dense gratings, and surface roughness measurements using three different classes of developer systems of varying solvation strength, ZED-N50, methyl isobutyl ketone (MIBK) : isopropyl alcohol (IPA) 1:3, and IPA : H2O 7:3, at the ambient temperature (22 °C) and cold (-15 °C) development conditions. In order to provide a deeper insight into the ZEP development process, we propose a novel kinetic model of dissolution for ZEP, and develop an efficient analytical method that allows determining the microscopic parameters of ZEP dissolution based on experimental contrast curves. We also observe experimentally and characterize the negative tone behavior of ZEP for dense grating patterning and compare its performance with positive tone behavior.