A short review on the advancement in the development of TiO2 and ZnO based photo-anodes for the application of Dye-Sensitized Solar Cells (DSSCs)

Population growth significantly expanding the boundaries of residential areas and living standards for humankind results in a tremendous increase in energy consumption. Unlike fossil fuels, which are found only in a few sites and non-renewable sources, solar energy is renewable and freely available in every part of the world. A dye-sensitized solar cell (DSSC) is a suitable electrochemical device to harness solar energy to produce power and is advantageous for its simplicity and inexpensive cost. Variations in photo-electrodes micro/nanostructure shape, doping, size, and crystal phase can improve the DSSCs performance by enhancing dye loading, improved light scattering ability, and/or faster electron transit and longer electron lifetime. The high yielding techniques for producing diverse morphologies for nanoparticles with appropriate band gaps might thus be considered another feasible strategy for improving cell performance. The impact of influencing parameters on photovoltaic characteristics of photo-anode for DSSC application is investigated in this review article. The descriptions are presented by compiling a list of relevant literature reports.

Optimal synthesis of polyelectrolyte nanogels by electrostatic assembly directed polymerization for dye loading and release

We fully address the process parameters of EADP regarding optimal and controlled preparation of PE nanogels. The response behaviour of the nanogels, and their take-up and release of charged dye molecule upon varying pH and salt are also investigated.

Effect of Acid Treatment in Dye Loading Capacity of Spin Coated ZnO Film

In recent times, the research on ZnO is growing tremendously, because of its potential use in many applications such as optical devices, dye sensitized solar cell (DSSC), gas sensors and biomedical. ZnO thin films of various thicknesses were prepared by the spin coating method using the zinc acetate precursor with diethanolamine and ethanol. The structural and optical characterizations of as-prepared ZnO films carried out using XRD and UV-Vis spectrophotometer, respectively. The XRD results showed polycrystalline wurtzite structure of ZnO. The average crystallite size of ZnO as calculated using Debye Scherrer’s formula was 26 nm. The optical band gap of ZnO was found to decrease with film thickness. The dye extracted from the leaves of Tectona Grandis (Sagun) which possesses a high and wide absorbance was used in this experiment. The study on the effect of acid treatment on ZnO films in dye loading showed enhanced absorbance in acid treated ZnO as compared to untreated ZnO.

2-Thiohydantoin Moiety as a Novel Acceptor/Anchoring Group of Photosensitizers for Dye-Sensitized Solar Cells

Very recently, we have reported the synthesis and evaluation of biological properties of new merocyanine dyes composed of triphenylamine moiety, π-aromatic spacer, and rhodanine/2-thiohydantoin-based moiety. Interestingly, 2-thiohydantoin has never been studied before as an electron-accepting/anchoring group for the dye-sensitized solar cells (DSSCs). In the presented study, we examined the applicability of 2-thiohydantoin, an analog of rhodanine, in DSSC technology. The research included theoretical calculations, electrochemical measurements, optical characterization, and tests of the solar cells. As a result, we proved that 2-thiohydantoin might be considered as an acceptor/anchoring group since all the compounds examined in this study were active. The most efficient device showed power conversion efficiency of 2.59%, which is a promising value for molecules of such a simple structure. It was found that the cells’ performances were mainly attributed to the dye loading and the ICT molecular absorption coefficients, both affected by the differences in the chemical structure of the dyes. Moreover, the effect of the aromatic spacer size and the introduction of carboxymethyl co-anchoring group on photovoltaic properties was observed and discussed.

Targeted Esterase induced Dye loading supports Calcium Imaging in Eukaryotic Cell-Free Systems

ABSTRACTCalcium imaging is an important functional tool for addressing ion channels, transporters and pumps for drug screening in living cells. Depicted eukaryotic cell-free systems utilize microsomes, derived from endoplasmic reticulum to incorporate the synthesized membrane proteins. Absence or inadequate amount of carboxylesterase in the endoplasmic reticulum of eukaryotic cells, which is necessary to cleave the acetoxymethyl ester moiety of the chemical calcium indicators, advocates the hindrance to perform calcium imaging in microsomes. In this work, we try to overcome this drawback and adapt the cell-based calcium imaging principle to a cell-free protein synthesis platform. Carboxylesterase synthesized in a Spodoptera frugiperda Sf21 lysate translation system is established as a viable calcium imaging tool and hTRPV1 is used as a model channel protein to demonstrate the realization of this concept.

Dyes Amount and Light Scattering Influence on the Photocurrent Enhancement of Titanium Dioxide Hierarchically Structured Photoanodes for Dye-Sensitized Solar Cells

In this study, we prepared and analyzed the properties of hill-like hierarchically structured titanium dioxide (TiO2) photoanodes for dye-sensitized solar cells (DSSCs). We expected that the presence of appropriately aggregated TiO2 clusters in the photoanode layer would translate to relatively strong light scattering and dye loading, increasing the photovoltaic efficiency. A detailed light-harvesting study was performed by employing polyvinyl alcohol (PVA) polymers of different molecular weights as binders for the aggregation of the TiO2 nanoparticles (P-25 Degussa). Hence, we obtained a series of TiO2 films, presenting a variety of morphologies. Their reflection, as well as absorbance of light by the attached dye, the amount of dye loading, and the performance of the fabricated DSSC devices were investigated. Our optimized device, with a relatively high dye loading and good light harvesting ability, was able to enhance the short-circuit current (Jsc) in the DSSCs by 23%.