Computational predictions of adaptive aromaticity for the design of singlet fission materials

Singlet fission has attracted extensive attention from experimentalists and theoreticians due to its ability to improve photovoltaic conversion efficiency. Still, designing singlet fission materials remains challenging. In this work, we...

Photovoltaics: towards ultimate performances

Photovoltaic conversion has made impressive progress since its discovery, but as will be discussed here, much can still be done. It is of interest to investigate what are the intrinsic limits of the technology. We call here ultimate performance those that could be limited only by intrinsic properties of the devices. This point will be discussed along three lines: ultimate limits for energy conversion, ultimate limits for material usage and ultimate limits for device stability.

Natural Waste to Electricity: Engineering Pomegranate Peels and Ag-Doped ZnO for Photovoltaic Applications

Utilization of natural waste for energy conversion offers the method for clean energy production with sustainable development. The pomegranate peels are the natural waste generated every day and we describe the conversion of this waste into electricity by a simple and cost-effective method. Dye Sensitized Solar Cells (DSSCs) offer simple and cost-effective method for the preparation of solar cells. The advantages include easy to fabrication, lower cost of the materials and electricity generation under low illumination indoor conditions. DSSCs involve two Transparent Conducting Oxide (TCO) photoelectrodes acting as photoanode and photocathode. In one photoelectrode, Semiconducting oxide (TiO2/ZnO) and dye (Natural/Organometallic) are coated that acts as photo-absorbing materials. The role of dyes and semiconducting material play an important role in determining the photovoltaic conversion efficiency of fabricated solar cells. In this work, hydrothermal method has been adopted for the preparation of pure and silver doped ZnO nanoparticles using polyethylene glycol (PEG) as capping agent via wet chemical route. The structural and optical properties of the prepared samples were studied using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Analysis (EDAX) and UV-Visible absorption spectra. A Natural dye from the peels of pomegranate was extracted and dye sensitized solar cells were fabricated with pure and Ag-doped nanoparticles. Both the materials showed the photovoltaic conversion capabilities and showed photoconversion efficiencies. The solar cell fabricated with Ag-doped ZnO semiconducting nanoparticle showed higher short circuit current density as compared to the pure ZnO-nanoparticle synthesized in this study. The photoconversion efficiency of the DSSC based on Ag-doped ZnO showed 30% more conversion efficiency than the cell without silver doping.

Performance simulation of semi-transparent photovoltaic glass on a skylight for commercial building

The demand for energy in buildings is a worldwide research subject due to its importance in the global electric load share. Besides, photovoltaic conversion to generate electricity locally is one of the ways to meet that demand. This work aims to evaluate the application of semi-transparent photovoltaic glass on a skylight of a commercial building and estimate electricity consumption and production using computational simulation with EnergyPlus. The opening size was set as a variable parameter. Its performance was compared to an ordinary skylight and opaque modules under the same conditions for three different Brazilian bioclimatic zones. Results show that the area's change provided significant differences in generation and less important ones in consumption. Among the bioclimatic zones, the building presented the lowest consumption and the highest generation for all configurations in the coldest zone, making it the best region for net electricity, i.e., purchased from a utility. Comparing semi-transparent with opaque modules, the latter produced much more energy, but consumption was reduced by an average of 28% in favour of the photovoltaic glass. The main conclusion is that the use of photovoltaic technology in a semi-transparent glass is promising regarding the integration of generators to the building, but the efficiency rates need to increase to bring it closer to opaque modules in performance.