The present research is focused on developing ZnAl2O4 (gahnite) spinel as an antireflection coating material for enhanced energy conversion of polycrystalline silicon solar cells (PSSC). ZnAl2O4 has been synthesized using dual precursors, namely aluminum nitrate nonahydrate and zinc nitrate hexahydrate in ethanol media. Diethanolamine has been used as a sol stabilizer in sol-gel process for ZnAl2O4 nanosheet fabrication. ZnAl2O4 nanosheet was deposited layer-by-layer (LBL) on PSSC by spin coating method. The effect of ZnAl2O4 coating on the physical, electrical, optical properties and temperature distribution in PSSC was investigated. The synthesized antireflection coating (ARC) material bears gahnite (ZnAl2O4) spinel crystal structure composed of two dimensional (2D) nanosheets. An increase in layer thickness proves the LBL deposition of ARC on the PSSC substrate. The ZnAl2O4 2D nanosheet comprising ARC on the PSSC was tested and it exhibited a maximum of 93 % transmittance, short-circuit photocurrent of 42.364 mA/cm2 and maximum power conversion efficiency (PCE) 23.42 % at a low cell temperature (50.2 °C) for three-layer ARC, while the reference cell exhibited 33.518 mA/cm2, 15.74 % and 59.1 °C, respectively. Based on the results, ZnAl2O4 2D nanosheets have been proven as an appropriate ARC material for increasing the PCE of PSSC.
K. Kathirvel, R. Rajasekar, T. Shanmuharajan, Samir Kumar Pal, P. Sathish Kumar and J. Saravana Kumar
Development of several viable renewable energy resources is in progress. Photovoltaics (PV) is one among those energy resources that provide clean and sustainable energy technology to replace fossil fuels  . In order to enhance the utilization of PV, powerconversionefficiency (PCE) and cost factor of silicon solar cells need to be considered. Multi-crystalline silicon (mc-Si) solar cells are cheaper and account for 50 % of PV modules manufactured worldwide due of their low manufacturing cost, high conversion efficiency under tropical
Dye sensitized solar cells are photoelectrochemical cells mimicking photosynthesis. They represent a new generation of solar cells which is intensively studied nowadays. This cell was fabricated using TiO2 nanoparticles coated on FTO glass, organic dyes as photosensitizer, PEDOT:PSS as counter electrode and iodide-triiodide as electrolyte. The present work aims at the use of low cost new organic dyes viz. biebrich scarlet, alizarine cyanine green and evans blue for DSSC as an alternative to metallic dyes. In the present work, I-V characteristics, energy or power conversion efficiencies of the dyes have been studied in different solvents. The photoelectrochemical properties of the dyes were observed under 1.5 AM condition.
Small molecules of ThQuTh, CzQuTh, CzQuCz and TPAQuCz were designed and synthesized, based on quinoxaline acceptor, and electron donating groups, i.e. alkyl-thioephene, carbazole and triphenylamine on both side chains and molecular backbones. Their thermal, optical and electrochemical properties were systematically compared and studied. The absorption spectra of the small molecules were strongly affected by the donor units attached to quinoxaline. Strong electron donating groups, such as carbazole on the molecular backbone would lower optical band gap, resulting in a wide absorption and the strong donor on the side chain would enhance the absorption intensity in short wavelength region. The highest occupied molecular orbital (HOMO) energy levels of the four molecules were up-shifted with increasing the electron donating properties of donor units. The bulk-heterojunction organic solar cells with a device structure of ITO/PEDOT:PSS/SMs:PC61BM/LiF/Al were fabricated, in which the small molecules functioned as donors while PC61BM as acceptor. Because the electron-donating ability of carbazole (Cz), triphenylamine (TPA) is higher than that of thiophene (Th), CzQuTh, CzQuCz and TPAQuCz show higher power conversion efficiency (PCE) than that of ThQuTh. Furthermore, being the strongest in absorption intensity and widest in absorption spectrum, TPAQuCz has the highest power conversion efficiency. Further improvement of the device efficiency by optimizing the device structure is currently under investigation
Liguo Jin, Hongjie Wang, Shuo Wang, Liping Wen, Jin Zhai and Tianxin Wei
A novel zinc porphyrin (5,10,15-tri-dodecoxyphenyl-20-(4-hydroxyphenyl-azo-benzenyl)-porphyrinatozinc (tdhab-ZnP)) with benzenyl-azo-phenolic group, able to adsorb on the nanocrystalline-TiO2 film, has been synthesized. We constructed a dye-sensitized solar cell based on the nanocrystalline-TiO2 hierarchical structure film, with a power conversion efficiency of 4.15 % and a high current density of 14 mA/cm2 under AM 1.5 irradiation. UV-Vis absorption spectra measurements indicated that the tdhab-ZnP molecules formed a charge transfer complex with TiO2 nanoparticles (NPs) through the phenolic group. Cyclic voltammetry measurement showed that the charge separation resulting from the tdhab-ZnP excited singlet state to the conduction band (CB) of TiO2 and charge shifting from the I−/I3− couple to the porphyrin radical cation were thermodynamically feasible.
Wojciech Luboń, Grzegorz Pełka, Konstanty Marszałek and Anna Małek
The outdoor measurements (during two months experiment) of photovoltaic silicon and CIGS modules as well as simulation of energy production during the period experiment are presented in this paper. This paper offer comparison of construction and electrical characteristics of multicrystalline silicon based modules and CIGS based modules. The measuring system for PV modules efficiency research is shown. The nominal power of installed modules is 250 W for m-Si and 280 W for CIGS modules. The energy production in outdoor conditions at direct current side and alternating current side of each photovoltaic panel was measured. Each PV panel was also equipped with temperature sensor for screening panel temperature. The photovoltaic panels were connected to the electrical network with micro inverters. To determine the influence of irradiance at sunshine on power conversion efficiency of PV panels, the pyranometer was installed in the plane of the modules. Measurement of the instantaneous power and irradiance gave the information about the efficiency of a particular photovoltaic panels. In the paper all data from research installation were analysed to present the influence of solar cell technology on the power conversion efficiency. The results of energy production show that m-Si module produced more energy from square meter (30.9 kWh/m2) than CIGS module (28.0 kWh/m2). Thin film module shows the higher production per kWp than multicrystalline module: 217.3 kWh/kWp for CIGS and 201.9 kWh/kWp for m-Si. The energy production simulation (made by PV SOL software and outdoor measurements test are in the good agreement. Temperature power coefficient for the CIGS module is twice lower than for the multicrystalline silicon module: 0.56%/°C and 0.35%/°C for m-Si and CIGS modules, respectively. The obtained results revealed strong influence of irradiance and temperature on energy production by PV panels. Performed studies have a large field of potential application and could improve designing process of PV installation.
In this paper, we have investigated the bulk heterojunction organic solar cells based on CuI — polyvinyl alcohol (CuI-PVA) nanocomposite as electron donor and [6,6] — phenyl C60 — butyric acid methyl ester (PCBM) or modified PCBM i.e. F as electron acceptor. The power conversion efficiencies (PCEs) of 0.46 % and 0.68 % were achieved for the photovoltaic devices based on as cast CuI-PVA:PCBM and CuI-PVA:F blend films, respectively. The higher PCEs of the organic solar cells based on F as electron acceptor resulted from the increase in both short circuit current (Jsc) and open circuit voltage (Voc), due to the increased absorption of F in visible region and its higher LUMO level. After thermal annealing, the PCEs of the organic solar cells were further increased to 0.54 % and 0.80 % for CuI-PVA:PCBM and CuI-PVA:F blends, respectively. The increase in the PCEs was mainly due to the increase in Jsc, which has been attributed to the improvement in hole mobility and broadening of the absorption band in the longer wavelength region. The improved hole mobility resulted in more balanced charge transport in the devices based on the thermally annealed blends.
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Antons Patlins, Andrii Hnatov, Shchasiana Arhun, Hanna Hnatova and Vasiliy Migal
. S. Yilbas, “Effect of Accumulation of Environmental Dust and Subsequent Mud Formation on Textural, Chemical, and Optical Properties of Silicon Wafers for Photovoltaic Cells”, IEEE Journal of Photovoltaics , vol. 8, no. 5, pp. 1274–1280, 2018. https://doi.org/10.1109/JPHOTOV.2018.2841498
 M. Gürtürk, H. Benli, and N. K. Ertürk, “Effects of different parameters on energy–Exergy and powerconversionefficiency of PV modules”, Renewable and Sustainable Energy Reviews , vol. 92, pp. 426–439, 2018. https://doi.org/10.1016/j.rser.2018.04.117
Wilmer Emilio García Moreno, Andressa Ullmann Duarte, Litiéle dos Santos and Rogério Vescia Lourega
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 B. Shin, Y. Zhu, N.A. Bojarczuk, S.J. Chey and S. Guha, “Control of an interfacial MoSe2 layer in Cu2ZnSnSe4 thin film solar cells: 8.9% powerconversionefficiency with a TiN diffusion barrier,” Applied Physics Letters, vol. 101, no. 5, 2012.
 F. Karg, “High Efficiency CIGS Solar Modules,” Energy Procedia, vol. 15, pp. 275–282, 2012.
 L. Han, A. Islam, H. Chen, C