Piper Ornatum and Piper Betle as Organic Dyes for TiO2 and SnO2 Dye Sensitized Solar Cells

Dye sensitized solar cell (DSSC) mimics the principle of natural photosynthesis are now currently investigated due to low manufacturing cost as compared to silicon based solar cells. In this report, we utilized Piper ornatum (PO) and Piper betle (PB) as sensitizer to fabricate low cost DSSCs. We compared the photovoltaic performance of both sensitizers with Titanium dioxide (TiO2) and Tin dioxide (SnO2) semiconductors. The results show that PO and PB dyes have higher Short circuit current (Jsc) when applied in SnO2 compared to standard TiO2 photo-anode film even though the Open circuit voltage (Voc) was hampered on SnO2 device. In conclusion, from the result, higher electron injections can be achieved by choosing appropriate semiconductors with band gap that match with dyes energy level as one of strategy for further low cost solar cell.The 2nd International Conference on Science (ICOS), 2–3 November 2017, Makassar, Indonesi

Cobalt-Based Electrolytes for Dye-Sensitized Solar Cells: Recent Advances towards Stable Devices

Redox mediators based on cobalt complexes allowed dye-sensitized solar cells (DSCs) to achieve efficiencies exceeding 14%, thus challenging the emerging class of perovskite solar cells. Unfortunately, cobalt-based electrolytes demonstrate much lower long-term stability trends if compared to the traditional iodide/triiodide redox couple. In view of the large-scale commercialization of cobalt-based DSCs, the scientific community has recently proposed various approaches and materials to increase the stability of these devices, which comprise gelling agents, crosslinked polymeric matrices and mixtures of solvents (including water). This review summarizes the most significant advances recently focused towards this direction, also suggesting some intriguing way to fabricate third-generation cobalt-based photoelectrochemical devices stable over time

Enhancing the Photovoltaic Performance of Dye-Sensitised Solar Cells for Building Integrated Applications

The building sector is responsible for more than one-third of global energy consumption. With increasing global population, the demand for energy efficiency buildings and on-site electricity production is rising. Building integrated photovoltaics (BIPV) is one of the most promising contributors to net-zero energy buildings, while also increasing the aesthetic value of the built environment. Among all the transparent solar cells, dye-sensitised solar cells (DSSCs) have low production cost, semi-transparency nature and a range of colours for building design. This thesis presents an overview of the current energy scenario and future prospects, state-of-the-art of photovoltaic technologies and the challenges in commercialising new generation solar cells. The first approach here is to find an efficient and low-cost alternative photoanode, sensitiser and counter electrode for DSSC. The tested materials are high surface area mesoporous TiO2, new ruthenium complex (m-HRD-1) sensitiser and Jet nebulizer spray coated CZTS. All the obtained results are compared with the commercial materials. Secondly, semi-transparent DSSCs are fabricated with different transparencies and their colour properties such as correlated colour temperature and colour rendering index are evaluated. Moreover, glazing properties and daylight glare analysis are studied to assess the possibility of adopting semi-transparent DSSCs into building architectures. Finally, a low solar concentrator is placed on the transparent-DSSCs to enhance their photovoltaic performance. The internal charge transfer mechanism of the DSSCs is also studied to understand the impact of the concentrated light. Furthermore, the performance of the concentrator coupled devices under different light intensities is studied. The results presented here provide a fertile base for further investigation, which will focus on improving the performance of all the new generation low cost solar cells using optical elements with new designs. The target is to improve the performance and stability of the transparent solar cell devices and use them as BIPV materials to overcome the challenges of the increasing energy demand

Tuning anatase-rutile phase transition temperature : TiO2/SiO2 nanoparticles applied in dye-sensitized solar cells

TiO2/SiO2 nanoparticles with 3, 5, and 10 molar percent of silica, were synthesized by hydrothermal method and characterized by SEM, TEM, N2 adsorption-desorption isotherms, X-ray diffraction, and Raman and UV-Vis spectroscopy. While pristine TiO2 thermally treated at 500°C presents a surface area of 36 m2g-1(±10 m2g-1), TiO2/SiO2 containing 3, 5, and 10 molar percent of silica present surface areas of 93, 124, and 150 m2g-1(±10 m2g-1), respectively. SiO2is found to form very small amorphous domains well dispersed in the TiO2 matrix. X-ray diffraction and Raman spectroscopy data show that anatase-to-rutile phase transition temperature is delayed by the presence of SiO2, enabling single-anatase phase photoanodes for DSSCs. According to the I×V measurements, photoanodes with 3% of SiO2 result in improved efficiency, which is mainly related to increasedsurface area and dye loading. In addition, the results suggest a gain in photocurrent related to the passivation of defects by SiO

Solar Cells

The second book of the four-volume edition of "Solar cells" is devoted to dye-sensitized solar cells (DSSCs), which are considered to be extremely promising because they are made of low-cost materials with simple inexpensive manufacturing procedures and can be engineered into flexible sheets. DSSCs are emerged as a truly new class of energy conversion devices, which are representatives of the third generation solar technology. Mechanism of conversion of solar energy into electricity in these devices is quite peculiar. The achieved energy conversion efficiency in DSSCs is low, however, it has improved quickly in the last years. It is believed that DSSCs are still at the start of their development stage and will take a worthy place in the large-scale production for the future

Optimisation and characterisation of alternative hole transporting media of dye-sensitised solar cells and stability study of perovskite solar cells

Dye-sensitised solar cells (DSSCs) are regarded as a possible alternative to silicon-based photovoltaics because of their potential for low-cost production. The processing of two alternative hole transport media, one for liquid-state DSSCs and the other for solid-state DSSCs is studied in this thesis. Also, research interest in methyl ammonium lead iodide perovskite solar cells has been increasing quickly. This thesis also reports some preliminary studies on the stability of TiO2/CH3NH3PbI3 perovskite solar cells. Water is not commonly used as a solvent in liquid electrolyte DSSCs, but there are many reasons to re-examine water, ranging from cost advantage to fundamental science. The first part of the thesis addresses the wetting and recombination issues of water-based DSSCs. DSSCs using only water as the solvent and guanidinium iodide/iodine as the redox couple have been fabricated and they operate at 4% energy efficiency under 1-sun illumination. The second part of this thesis studies melt-processing of hole transport materials. This technique overcomes the problem of poor pore filling which is commonly observed in solid-state dye-sensitised solar cells. It is found that the low efficiency of melt-processed DSSCs is due to the heat applied during the melting process which causes a decrease in recombination lifetime. Solid-state DSSCs made with melt-processed spiro-OMeTAD are shown, with a maximum efficiency of 0.45 %. Stability of TiO2/CH3NH3PbI3 perovskite solar cells is examined in the third part of the thesis. Most literature in the perovskite solar cells focuses on the efficiency of devices, with little attention being paid to stability. A TiO2/CH3NH3PbI3 solar cell has been exposed to 40 sun-equivalent constant illumination for 63 hours (which delivers over 2700 hours equivalent of 1 sun photo-excitations). The loss in the cell’s Jsc was only 7 %, however the loss in Voc was 190 mV (24 %) at 1 sun.Open Acces

Investigating the Charge-Transfer Dynamics of Single-Molecule Sensitizers

Dye-sensitized solar cells (DSSCs) can reduce the cost of photovoltaic electricity generation to meet global energy needs. Optimizing DSSC efficiency requires a detailed understanding of the underlying charge transfer processes at the dye-semiconductor interface. By modifying the sensitizer structure, we gain insight into these charge transfer mechanisms. In this thesis, two hydroxyanthraquinone dyes are compared to investigate the impact of structure on charge-transfer and photobleaching dynamics. A combination of ensemble-averaged and single-molecule spectroscopy approaches are used to interpret the underlying ET kinetics