This document describes a study on organic materials with trans-stilbene chromophores for dye-sensitized solar cells. The researcher designed and synthesized a series of molecules containing trans-stilbene bridges linked to electron donors and acceptors through para or meta conjugation. Testing showed the para-conjugated compound had the best power conversion efficiency at 5.34%, while the meta-conjugated compound achieved a still good 2.89% efficiency. Meta conjugation inherently has weaker electronic coupling but can prolong excited state lifetimes. However, it also shortens the conjugation system, limiting photocurrent formation. Further work is needed to improve meta-conjugated materials through molecular structure optimization.
Biological method for the preparation of nanoparticles(Sheersho)Sheersha Pramanik 🇮🇳
I have described about the biological processes(other than physical,chemical) for the preparation of Nanoparticles.
do like comment share if you like it.
— In the present work, impact of UV-B radiation (280-
315nm: 0.4 W m-2) on growth, photosynthetic pigments, protein,
ascorbate, proline and lipid peroxidation have been studied in
two cyanobacteria Nostoc muscorum and Synechocystis PCC
6803. UV-B radiation (2 to 6 hrs) leads to 55% inhibition of
growth in Synechocystis PCC 6803 in comparison to control
where as in Nostoc muscorum growth reduces up to 45%. This
UV-B treatment also significantly decreased the contents of
chlorophyll, carotenoids and phycocyanin. Photosynthetic
pigments decreased with increasing doses of UV-B (2 to 6 hrs)
radiation. However, the inhibitory effect in Synechocystis PCC
6803 was more pronounced than in Nostoc muscorum. With
increasing UV-B exposure period, production of ascorbate (19-
45%), proline (12-29%) and lipid peroxidation was significantly
higher in Synechocystis PCC 6803 as compared to control
sample. It was observed that lipid peroxidation enhanced 33 %
than control sample of Synechocystis PCC 6803. Our result shows
that photosynthetic apparatus is the main target of UV-B
radiation causing degradation of photosynthetic pigments. This
study concluded that Synechocystis PCC 6803 was the susceptible
organism for survival in stress condition than Nostoc muscorum.
Biological method for the preparation of nanoparticles(Sheersho)Sheersha Pramanik 🇮🇳
I have described about the biological processes(other than physical,chemical) for the preparation of Nanoparticles.
do like comment share if you like it.
— In the present work, impact of UV-B radiation (280-
315nm: 0.4 W m-2) on growth, photosynthetic pigments, protein,
ascorbate, proline and lipid peroxidation have been studied in
two cyanobacteria Nostoc muscorum and Synechocystis PCC
6803. UV-B radiation (2 to 6 hrs) leads to 55% inhibition of
growth in Synechocystis PCC 6803 in comparison to control
where as in Nostoc muscorum growth reduces up to 45%. This
UV-B treatment also significantly decreased the contents of
chlorophyll, carotenoids and phycocyanin. Photosynthetic
pigments decreased with increasing doses of UV-B (2 to 6 hrs)
radiation. However, the inhibitory effect in Synechocystis PCC
6803 was more pronounced than in Nostoc muscorum. With
increasing UV-B exposure period, production of ascorbate (19-
45%), proline (12-29%) and lipid peroxidation was significantly
higher in Synechocystis PCC 6803 as compared to control
sample. It was observed that lipid peroxidation enhanced 33 %
than control sample of Synechocystis PCC 6803. Our result shows
that photosynthetic apparatus is the main target of UV-B
radiation causing degradation of photosynthetic pigments. This
study concluded that Synechocystis PCC 6803 was the susceptible
organism for survival in stress condition than Nostoc muscorum.
Electrochemical behaviorof carbon paste electrode modified with Carbon Nanofi...IJERA Editor
The electrochemical behavior of carbon paste electrode modified with carbon nanofibers has been studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scaning electron microscopy. The response of modified electrodein ferroferricyanidesolutionshows reversible behavior and significant increment in current value compared to the bare CPE indicating that CNFs act as efficient electron mediator to catalyze reactions at the surface. The modified electrode has been used to study the electrochemical response of bisphenol Ausing different electrochemical techniques such as cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry and square wave voltammetry. The oxidation peak of BPA was observed at about 0.53 V in phosphate buffer solution at pH 6.7. The oxidation peak current of BPA varied linearly with concentration over a wide range of 5µmol L-1 to 400 µmol L-1 and the detection limit of this method was found to be 0.55 µmol L
Term ‘Nano’ comes from the Greek word ‘nanos’ meaning dwarf and denotes a measurement on the scale of one billionth (10⁹) of a meter in size. Nanoparticles are defined as a particulate dispersions of solid particles with atleast one dimension at a size range of 10-1000 nm. The most important feature of Nanoparticles is their surface area to volume aspect ratio, allowing them to interact with other particles easier.
Electrochemical behaviorof carbon paste electrode modified with Carbon Nanofi...IJERA Editor
The electrochemical behavior of carbon paste electrode modified with carbon nanofibers has been studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scaning electron microscopy. The response of modified electrodein ferroferricyanidesolutionshows reversible behavior and significant increment in current value compared to the bare CPE indicating that CNFs act as efficient electron mediator to catalyze reactions at the surface. The modified electrode has been used to study the electrochemical response of bisphenol Ausing different electrochemical techniques such as cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry and square wave voltammetry. The oxidation peak of BPA was observed at about 0.53 V in phosphate buffer solution at pH 6.7. The oxidation peak current of BPA varied linearly with concentration over a wide range of 5µmol L-1 to 400 µmol L-1 and the detection limit of this method was found to be 0.55 µmol L
Term ‘Nano’ comes from the Greek word ‘nanos’ meaning dwarf and denotes a measurement on the scale of one billionth (10⁹) of a meter in size. Nanoparticles are defined as a particulate dispersions of solid particles with atleast one dimension at a size range of 10-1000 nm. The most important feature of Nanoparticles is their surface area to volume aspect ratio, allowing them to interact with other particles easier.
1. 國立臺灣師範大學化學系國立臺灣師範大學化學系國立臺灣師範大學化學系國立臺灣師範大學化學系
Department (Graduate institute) of Chemistry,
National Taiwan Normal University
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應用於染料敏化太陽能電池應用於染料敏化太陽能電池應用於染料敏化太陽能電池應用於染料敏化太陽能電池
Dipolar Organic Materials with trans-Stilbene
Chromophore for Dye-Sensitized Solar Cells
徐榕蓉徐榕蓉徐榕蓉徐榕蓉
Jung Jung Hsu
指導教授指導教授指導教授指導教授：：：：周大新周大新周大新周大新 博士博士博士博士
Adviser：：：：Tahsin J. Chow, Ph.D.
中華民國中華民國中華民國中華民國一一一一○○○○一一一一年七月年七月年七月年七月
July, 2012
3. 3
Abstract
A series of trans-stilbene moiety dyes were designed and synthesized
based on the donor-bridge-acceptor (D-B-A) system for the application of
dye-sensitized solar cells. Besides the typical para conjugation, the
meta-bridge dyes were developed in order to examine the difference of
structural effect. The ideal bridge would promote electron transfer from
donor to acceptor while resisting electron transfer in the reverse direction
and thus suppressing charge recombination. In addition the ionic liquids
electrolytes and different dye baths have been used to investigate the
performance and the characteristics.
It is inherently that electronic coupling through a meta-bridge is
weaker than through a para one, however recent studies the meta-bridge
undergoes enhanced electronic coupling in the excited state. The
meta-bridge isomers shorten conjugation system, to cause the
photocurrent transport trapped inevasible and low JSC. Thence the meta
conjugation effect should be further study in terms of molecular structure,
and looking forward to overcome this drawbacks. In our study a
well-known dye (PP) shows a prominent solar-to-energy conversion
efficiency (η) 5.34%, and a meta conjugated dye (PPM) also shows
2.89%.
Key Words：trans-Stilbene/ Dye-Sensitized Solar Cells/ meta Conjugation
