Dye Sensitized Solar cell

The dye-sensitized solar cell (DSSC) has been proven to have a good chance to become a notable competitor for solar cells based on today technology of p-n junction. The principle of operation of DSSC solar cells in comparison with conventional semiconductor solar cells where light absorption and charge carrier transport are done by the semiconductor is different. In DSSC these two tasks are separate. Charge separation is done by photo-induced injection to the conduction band and such created carriers are transported to charge collector. By using dyes which have broad absorption band, the solar cell is capable to harvest large fraction of sunlight. In this paper the basic construction and mode of operation of solar cells based on dyes is described.

Boron-dipyrrin dyes, through rational design, yield promising new materials. With strong electron-donor functionalities and anchoring groups for attachment to nanocrystalline TiO(2), these dyes proved useful as sensitizers in dye-sensitized solar cells. Their applicability in a solid-state electrolyte regime offers additional opportunities for practical applications.

Industrially viable assembly techniques have been established for dye solar cells to be used in low light (indoor) and outdoors applications. Stability behavior under thermal stress, UV and visible light irradiation is investigated, in particular in view of real outdoors conditions. Solid-state dye solar cells were also assembled, where an organic p-type semiconductor material replaces the currently employed liquid electrolyte.

Article History Keywords Dye-sensitized solar cells Photoanode Compact layer Ag nanoparticles Plasmonic device Fermi level shifting. High performance TiO2 photoanodes undoped and doped with silver nanoparticels of size about 15 nm were fabricated. Employing these electrodes dye-sensitized solar cells (DSSCs) were fabricated using N719 dye as sensitizer and iodide-triodide as redox couple. Current-voltage measurements were performed under the illumination of 100 mW cm-2 (AM 1.5). The electrical parameters of the fabricated cells were extracted from the current-voltage data that include open-circuit voltage, short-circuit current, shunt resistance, series resistance, fill-factor, ideality factor and solar energy-to-electricity conversion efficiency. The comparison of parameters revealed improvement in both the photovoltaic and electrical parameters of the plasmonic cell. The conversion efficiency measured for the reference cell without Ag NPs in TiO2 was 7.43 %, whereas the efficiency of plasmonic device with TiO2:Ag NPs was 9.26 %, resulting an overall efficiency improvement of 23% with Ag NPs. The increased performance of the plasmonic DSSC can be assigned to the improvement of its photovoltaic and electrical parameters. The improved short-circuit photocurrent density appears to be boosted due the enhanced light harvesting capability of the photoanode caused by the localized surface plasmon resonance effect induced in Ag nanoparticles. While, the rise in Voc can be credited to the upward shift of Fermi level of TiO2 due to the dopping of Ag nanoparticles in TiO2 network. Contribution/Originality: This study is based on one of the few attempts on photoanode engineering employing plasmonic effect for developing higher efficiency DSSCs. The comparison with the existing data has revealed significant improvement in the photovoltaic and electrical properties of the plasmonic device. This study has reported that Ag nanoparticles hold a unique plasmonic effect employing which performance parameters of the DSSC are improved much greater as compared to other metallic nanoparticles.

The incessant demand for energy forces us to seek it from sustainable resources; and concerns on environment demands that resources should be clean as well. Metal oxide semiconductors, which are stable and environment friendly materials, are used in photovoltaics either as photoelectrode in dye solar cells (DSCs) or to build metal oxide p–n junctions. Progress made in utilization of metal oxides for photoelectrode in DSC is reviewed in this article. Basic operational principle and factors that control the photoconversion efficiency of DSC are briefly outlined. The d-block binary metal oxides viz. TiO2, ZnO, and Nb2O5 are the best candidates as photoelectrode due to the dissimilarity in orbitals constituting their conduction band and valence band. This dissimilarity decreases the probability of charge recombination and enhances the carrier lifetime in these materials. Ternary metal oxide such as Zn2SnO4 could also be a promising material for photovoltaic application. Various morphologies such as nanoparticles, nanowires, nanotubes, and nanofibers have been explored to enhance the energy conversion efficiency of DSCs. The TiO2 served as a model system to study the properties and factors that control the photoconversion efficiency of DSCs; therefore, such discussion is limited to TiO2 in this article. The electron transport occurs through nanocrystalline TiO2 through trapping and detrapping events; however, exact nature of these trap states are not thoroughly quantified. Research efforts are required not only to quantify the trap states in mesoporous metal oxides but new mesoporous architectures also to increase the conversion efficiency of metal oxide-based photovoltaics.

A precise numerical model based on Kirchhoff's laws is used in investigating dye-sensitized solar cell (DSC) modules. As the I–V curve of a small DSC is obtained, the performances of DSC modules with any geometrical character can be exactly simulated by this model. By simulation, we find that the poor synchronization of work status in each cell is the main cause of low efficiency of large area module besides the Joule losses in the resistances. The optimized geometry parameters of the DSC module are mainly influenced by the manufacturing technique rather than the performance of the small cell. Simulation shows that the large area DSC module with aperture area efficiency of 10.57% can be produced based on the small cell with efficiency of 11.1%.► A precise model was used in dye-sensitized solar cell modules. ► Work details of the modules were investigated by this model. ► Synchronization of work status was found to be the main cause of power loss. ► Main parameters which influenced the performance of modules were optimized.