Design and Implementation of a Photovoltaic Characterization Platform at FaST

The site that houses the FaST faces high dusty winds and considerable temperature variation. Weather conditions such as solar radiation, temperature, and wind speed greatly affect the performance of PV modules. But the data from PV equipment manufacturers do not allow for proper sizing. Therefore, a rigorous study is needed to find the most suitable PV module technology for the study area. For this purpose, platforms for the acquisition of meteorological parameters and module characterization are indispensable. This platform project at FaST will serve training and pedagogy because its configuration will allow master and bachelor students to carry out practical work, to carry out studies on new cell technologies under the influence of external factors specific to the sub-Saharan zone and will bring an added value by providing additional information on real conditions and especially the influence of local external factors. Our study consisted first of all in the realization of the platform on the roof of the FaST, then in the design and the programming of a module of acquisition of the measured parameters on the basis of the Arduino microcontroller card and finally in the test of characterization of the modules used for the platform thanks to an electronic load on the basis of MOSFET of power controlled by a microcontroller that we realized.

New Carbazole-Based Organic Dyes with Various Acceptors for Dye-Sensitized Solar Cells: Synthesis, Characterization, DSSCs Fabrications and DFT Study

The molecular configuration, synthesis and characterization of (E)-3-(6-bromo-9-phenyl-9H-carbazol- 3-yl)acrylic acid (BPA), (E)-3-(6-bromo-9-phenyl-9H-carbazol-3-yl)-2-cyanoacrylic acid (BPCA) and (E)-N′-((6-bromo-9-phenyl-9H-carbazol-3-yl)methylene)-2-cyanoacetohydrazide (BPCH) configured D-π-A sensitizers and the sensitizers are used in DSSCs. Dye molecules are described by FT-IR, NMR and UV-Vis analysis. The study shows that the non-planar structure of BPA, BPCA and BPCH can effectively slow down the aggregation and conjugation of the dye. Computed vibrational modes are compared with observed bands. The Frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) have also been calculated using DFT-B3LYP/6-311++G(d,p) basis set. Physical-chemical parameters have also been analyzed using density functional theory. The most excellent DSSC performance in photovoltaic characterization is demonstrated by the dye molecules.

Optical Characterization and Photovoltaic Performance Evaluation of GaAs p-i-n Solar Cells with Various Metal Grid Spacings

GaAs p-i-n solar cells are studied using electroreflectance (ER) spectroscopy, light beam induced current (LBIC) mapping and photovoltaic characterization. Using ER measurements, the electric field across the pn junction of a wafer can be evaluated, showing 167 kV/cm and 275 kV/cm in the built-in condition and at −3 V reverse bias, respectively. In order to understand the effect of the interval between metal grids on the device’s solar performance, we performed LBIC mapping and solar illumination on samples of different grid spacings. We found that the integrated photocurrent intensity of LBIC mapping shows a consistent trend with the solar performance of the devices with various metal grid spacings. For the wafer used in this study, the optimal grid spacing was found to be around 300 μm. Our results clearly show the importance of the metal grid pattern in achieving high-efficiency solar cells.

Semi-Transparent Energy-Harvesting Solar Concentrator Windows Employing Infrared Transmission-Enhanced Glass and Large-Area Microstructured Diffractive Elements

We report on the study of energy-harvesting performance in medium-size (400 cm2) glass-based semitransparent solar concentrators employing edge-mounted photovoltaic modules. Systems using several different types of glazing system architecture and containing embedded diffractive structures are prepared and characterized. The technological approaches to the rapid manufacture of large-area diffractive elements suitable for use in solar window-type concentrators are described. These elements enable the internal deflection and partial trapping of light inside glass-based concentrator windows. We focus on uncovering the potential of pattern-transfer polymer-based soft lithography for enabling both the improved photon collection probability at solar cell surfaces, and the up-scaling of semitransparent solar window dimensions. Results of photovoltaic characterization of several solar concentrators employing different internal glazing-system structure and diffractive elements produced using different technologies are reported and discussed.