Topology optimization for high-resolution designs : Application in solar cell metallization

This paper describes a freeware program that computes the optical losses associated with the front surface of a silicon solar cell. The optical losses are not trivial to assess because (i) the refractive index and extinction coefficient of silicon, antireflection coatings (ARCs), and encapsulants varies with wavelength; (ii) cells are usually textured such that the light reflects multiple times from the front surface; (iii) light can be polarised, particularly after the first ‘bounce’ from a textured surface; and (iv) the incident spectrum and the cell's quantum efficiency varies with wavelength. The freeware program takes all of these aspects into account to calculate reflection from the solar cell, absorption in the ARCs, transmission into the silicon, and the equivalent current that is generated for any given spectrum. When modelling textured silicon, the program is restricted to normally incident light and pyramidal morphologies. The program computes solutions within one second for regular upright pyramids, regular inverted pyramids, and random upright pyramids—making it much faster than ray tracing. We provide an example of how the freeware can be employed to determine the optimal thickness of an ARC with and without encapsulation. The example demonstrates that the optimal thickness cannot be determined from reflection measurements when absorption in the ARCs is significant. The program is readily adaptable to assess ARCs on glass and thin-film solar cells.

Canal top solar panels: A unique nexus of energy, water, and land

This research examines the effectiveness of swarm intelligence approaches in improving the functioning of solar cell hybrid microgrids, specifically focusing on the difficulties caused by the irregularity of renewable energy sources. Analyzed were simulated data that represented the creation of solar cell and solar cell electricity, the status of charge of batteries, and the outputs of swarm optimization. The solar cell power data exhibited oscillations in power output ranging from 85 kW to 150 kW, corresponding to changes in solar cell speed ranging from 6.5 m/s to 9.0 m/s. On the other hand, solar cell power saw a marginal decrease from 95 kW to 88 kW, which may be attributed to variations in solar cell irradiation ranging from 850 W/m² to 780 W/m². The battery's level of charge varied between 70% and 95%, indicating the fluctuating rates of charging and discharging, which ranged from 20 kW to 30 kW and 12 kW to 25 kW, respectively. The swarm optimization rounds showed a decrease in the cost of the optimum solution from 3200 to 2000, and an improvement in the convergence rate from 80% to 100%. The analysis indicated a significant 76.5% surge in solar cell power output at peak periods, whereas there was an 8% decline in solar cell power. The state of charge (SoC) of the battery exhibited an average rise of 35.7%, while swarm optimization demonstrated a 37.5% reduction in cost and a steady 25% improvement in convergence rate. The results emphasize the natural fluctuation of renewable sources and demonstrate the potential of swarm intelligence in improving microgrid operation. These results highlight the significance of adaptive control methods in the management of renewable-based microgrids, providing valuable insights for improving their stability, dependability, and cost-effectiveness. The study's findings have practical applications, highlighting the importance of swarm intelligence in promoting the development of sustainable energy systems in the context of integrating renewable energy sources.

In solar cell production, metallization is the manufacturing of metal contacts at the surfaces of solar cells in order to collect the photo-generated current for use. Being one of the most expensive steps in solar cell fabrication, it plays both an electrical and an optical role, because the contacts contribute to shading, and to the series resistance of solar cells. In addition, metal contacts may reduce the solar cells voltage due to charge carrier recombination at the metal / silicon interface. Addressing these challenges could increase solar cell conversion efficiency while cutting their production costs. This work presents state of the art methods for the metallization of crystalline Si solar cells for industrial production as well as for research and development. Different metallization technologies are compared, and ongoing RD activities for the most relevant silicon solar cell metallization technologies are described in detail. Chapters cover fundamentals of metallization and metallization approaches, evaporated, plated and screen-printed contacts, alternative printing technologies, metallization of specific solar cell types, module interconnection technologies, and also address module technology. Written by a selection of world-renowned experts, the book provides researchers in academia and industry, solar cell manufacturing experts and advanced students with a thorough and systematic guide to advanced metallization of solar cells.

Screen printable copper pastes for silicon solar cells

The increasing reliance on renewable energy sources, such as solar power, necessitates accurate forecasting to ensure efficient grid integration and stability. This study explores the application of deep learning techniques, particularly deep neural networks (DNNs), in predicting solar irradiance and power output. By leveraging advanced algorithms and large datasets, this research aims to enhance the precision of solar energy forecasts, thereby optimizing grid management and resource allocation. Deep learning techniques, characterized by their ability to model complex nonlinear relationships, offer significant advantages over traditional statistical methods in forecasting solar energy. This study focuses on the development and evaluation of deep neural networks for predicting solar irradiance, which directly influences the power output of photovoltaic (PV) systems. The models are trained on extensive historical weather data, satellite imagery, and real-time solar output measurements to capture temporal and spatial variations in solar energy. Key components of the research include data preprocessing to handle missing values and noise, feature extraction to identify relevant patterns, and model training using various architectures of DNNs such as convolutional neural networks (CNNs) and recurrent neural networks (RNNs). The study also employs ensemble learning techniques to combine predictions from multiple models, further enhancing forecast accuracy. Results demonstrate that deep neural networks significantly outperform traditional forecasting methods in terms of accuracy and reliability. The improved forecasts enable better scheduling of energy generation and distribution, reducing reliance on fossil fuels and minimizing grid imbalances. Additionally, accurate solar energy predictions support the efficient integration of solar power into the grid, enhancing overall system stability and reducing operational costs. The study also addresses challenges in implementing deep learning models, such as computational requirements and the need for large, high-quality datasets. Solutions include leveraging cloud computing resources and developing standardized data collection protocols to facilitate broader application and scalability of the models. Application of deep learning techniques in solar energy forecasting represents a promising advancement for the renewable energy sector. By improving the accuracy of solar irradiance and power output predictions, deep neural networks contribute to more reliable grid integration and efficient energy management. This research advocates for the continued exploration and adoption of advanced machine learning methods to support the transition to a sustainable energy future. Keywords: Deep Learning Techniques; Solar Energy; Forecasting; Grid Integration; Power Output.

As our fossil sources of electricity reduce consistently, then looking for alternative electricity solutions turns into crucial. Solar cells often made from expensive materials, which is why much research focused on finding cheaper materials to reduce the overall cost of solar energy. Another way to overcome this problem is to use a solar concentrator - a cheaper light-absorbing material that covers a large area, which absorbs, directs, and focuses the light to a smaller area that contains actual solar cells. The interest in exploiting solar electricity for photovoltaic energy has grown dramatically in the latest years, furthermore essential improvements inside the solar cells’ efficiency with luminescent up or down converters have currently anticipated theoretically. While solar cells are still expensive, fewer of them needed to produce a certain amount of electricity because they receive more sunlight. This paper gives, in short, evaluate the usage of luminescent solar concentrator (LSC) as opportunity electricity has low fees and comfortable as compared with photovoltaic solar panels, reviewing extra benefits in actual existence applications primarily in high structures home windows and displays of electronic devices.

Toward improving the performance of Cu2ZnSnS4-based solar cells with Zr, W or sulfurized layers at the SnO2:F/Cu2ZnSnS4 rear interface

Hydrogen energy is expected to contribute to a decarbonized society because it does not emit CO2 during combustion. In particular, CO2 emissions from hydrogen production can also be prevented by utilizing renewable energy such as solar light and wind power. As water electrolysis is one of major hydrogen production methods, combination of water electrolysis and solar cell can make hydrogen production without CO2 emission. However, single solar cells usually have not enough voltage to electrolyze water. Therefore, modularization of several solar cell units is needed to electrolyze water to hydrogen. We have fabricated organic thin-film solar cells using organic materials in the photoelectric conversion layer and have aimed to achieve highly efficient conversion of light energy to hydrogen energy through water electrolysis using these cells. In this study, we fabricated solar cell modules for water electrolysis using two donor polymers, P3HT and PBDB-T and fullerene derivative, PC61BM and two non-fullerene acceptors, ITIC and IT-4F. The solar cell architecture consisted of indium tin oxide (ITO) cathode/ZnO/photoactive layer/MoO3/Ag anode. ZnO was deposited by sol-gel method, polymer donor:fullerene or non-fullerene acceptor by spin coating method, and MoO3 and Ag by vacuum deposition method. First, three types of solar cells composed of A fullerene-based P3HT:PC61BM, non-fullerene-based PBDB-T:IT-4F and PBDB-T:ITIC were fabricated, and their performance was evaluated using a solar simulator. The short-circuit current density (Jsc) and open-circuit voltage (Voc) were increased by changing to the non-fullerene system, indicating that the non-fullerene system has longer wavelength absorption and larger energy gap between HOMO of donor polymer and LUMO of acceptor, respectively. In addition, the PBDB-T:ITIC system was expected to reduce the number of series solar cell units in the module for water electrolysis because Voc was higher than that of the PBDB-T:IT-4F system. The photovoltaic performance of the PBDB-T:ITIC system was then evaluated by changing film thickness in the PBDB-T:ITIC solar cell. Jsc reached its maximum at the film thickness indicating absorbance of 0.73 at 637 nm, while Voc did not depend on film thickness, and the fill factor (FF) decreased with increasing film thickness. As a result, the power conversion efficiency (PCE) was achieved to be 6.75%. Currently, the maximum output voltage (Vmax) is 0.63 V. Therefore, it was found that a module with three single solar cell units connected in series on the same substrate was required in order to achieve above the voltage of 1.23 V, which is thermodynamically necessary for water electrolysis.3-cell series module with an area of 1.16 cm2 per cell were fabricated and their performance was evaluated. As a result, ideally, a 3-cell series module would have similar Jsc to that of a single solar cell, and Voc becomes about 3 times that of a single solar cell. However, the 3-cell series module has a particularly low FF of 0.40 compared to 0.48 for the single solar cell, resulting in decrease in PCE to 4.38%. To investigate the effect of cell area, single-cell solar cells with 1.16 and 0.126 cm2 were then fabricated and evaluated for performance. Jsc and Voc are comparable whereas FF is 0.57 for the small area, while it is lower at 0.48 for the large one. This indicates that an increase in area leads to an increase in series resistance and a decrease in FF. In addition, to investigate the effect of module structure, we evaluated the performance of 3 single solar cells with a cell area of 1.16 cm2 connected in series and parallel by crocodile clip. As a result, a large decrease in FF was observed for both connections, suggesting that crosstalk happened, caused by that ZnO, the electron transport layer was uniformly coated on the substrate. We will examine whether the performance of single solar cells can be maintained by changing the module structure.

This report summarizes work on improving solar cell conversion efficiencies by modifying the cell cover glass. Two approaches were investigated during the course of this work: grooved cover glasses to reduce the effect of top contact obscuration and secondary concentrators to improve concentrator solar cell performances in tracking modules. The grooved cover glass work used an array of metallized V shaped grooves in a thin cover glass (plastic) window to deflect incident light rays away from solar cell front surface regions covered by the solar cell electrical contact metallization onto unobstructed, optically active regions of the solar cell. Secondary concentrators are being considered for use on concentrator solar cells to improve overall system conversion efficiency and reduce receiver module cost. Secondary concentrators designed and fabricated during this project consist of small glass cones to attach directly to the top of the receiver solar cell. When appropriately designed, these secondary concentrator glass cones increase sunlight concentration on the solar cell, improve solar flux uniformity on the cell, improve system tolerance to tracking error, and allow for concentration ratios greater than can be ordinarily achieved with acrylic Fresnel lenses.

Solar energy is now (hopefully!) being used to provide electricity for a suite of computers in the science building at Cardinal Hinsley School, Willesden, West London, as the first of 100 solar panel systems to be allocated to UK schools or colleges by the year 2000. A total of 17 sites around the country have been selected to receive such systems under the UK Government's Foresight Scolar programme, involving Government, industry and education providers working together, and they should give first-hand experience to the generation that will see the technology come into its own. The solar electric panels at Cardinal Hinsley School are arranged into a canopy over the door of a building used for the school's Renewable energy club, run by Physics teacher George Nagle. A computer complete with teaching material is included in the package, giving access to the Internet and acting as the virtual centre of the network. It is intended that the school will act as a demonstration site for photovoltaic technology and, together with the teaching aids, stimulate further interest in renewable energy in the community. Schools taking part in the Scolar programme can consider a range of solar electric designs such as window louvres and wall cladding for existing or new buildings. Each school will contribute around one third of the cost of the system (typically £4000). The programme itself is a collaboration between the Government and British expertise in solar electricity from industry and universities, managed by the Intersolar Group. Solar power should make a positive contribution towards the UK's target of achieving 10% of the country's electricity from renewable energy sources by 2010. And meanwhile, for those gazing heavenwards, the popular planetarium at Techniquest, Cardiff's Science Discovery Centre, has been supplied with new projection equipment to widen the scope of its presentations. A choice of still or moving images of stars and planets will now be possible, along with a more detailed view of the night sky, and a sound system has also been installed. A range of new shows for schools and the general public has been designed to take full advantage of the improved facilities. Techniquest is in Stuart Street, Cardiff CF1 6BW (tel: 01222 475475).

III-nitride wide bandgap semiconductors have been at the center stage of the semiconductor R & D effort over the last decade. Photonic/electronic devices based on III-nitrides, including UV/blue/green/white LEDs, violet/blue LDs, UV detectors, and high power/temperature transistors, have reached high performance level. This talk will provide a brief overview on recent advances made by our group and others in the area of III-nitrides for energy and hydrogen generation. The presentation will concentrate on topics of material and device challenges of III-nitride solar cells and photoelectrochemical cells (PECs). The bandgap of InGaN expands from about 0.65 to 3.4 eV, which covers the entire solar spectrum. In principle, a multi-junction solar cell based on multiple layers of InGaN with different In-contents is capable of capturing the entire spectrum of the sunlight and can thus be highly efficient. To count for the relatively low materials quality for high In content InGaN alloys, InGaN/GaN multiple quantum wells (MQWs) have been adopted for the construction of nitride solar cells. We have grown, fabricated, and characterized InGaN based solar cells utilizing the InGaN/GaN MQWs p-i-n structures.1-3The fabricated solar cells exhibited open circuit voltage of about 2 V, a fill factor of about 60% and overall efficiency of about 3% under AM 1.5 irradiation. The performance of these nitride solar cells under concentrated sunlight has also been investigated. In additional to its bandgap match to the solar spectrum, the bandgap of InGaN alloys can also be engineered to optimally match with conditions necessary for direct hydrogen generation by water splitting using sunlight.4-6 The results on hydrogen gas generation via solar water splitting accomplished using n- and p-type InGaN epilayer as working electrodes will be discussed. Direct solar water splitting and hydrogen gas generation under zero bias has been realized using an InGaN/GaN multiple quantum well solar cell as a photoelectrochemical cell. Under the irradiation by a simulated sunlight (AM1.5G solar simulator), a 1.5% solar-to-fuel conversion efficiency has been achieved under zero bias, setting a new benchmark of employing III-nitrides as photoreactive electrodes for artificial photosynthesis. Time dependent hydrogen gas production photocurrent measured over a prolonged period revealed an excellent chemical stability of InGaN in aqueous solution. Our results indicate that InGaN is an excellent artificial photosynthesis material which is capable to provide usable clean fuel (hydrogen gas) with the sunlight being the only energy input. InGaN materials growth effort was supported by NSF (DMR-1206652) and the energy device effort was by DOE (FG02-09ER46552). Jiang & Lin are grateful to AT&T Foundation for the support of Ed & Linda Whitacre endowed chairs. R. Dahal, B. Pantha, J. Li, J. Y. Lin, and H. X. Jiang, “InGaN/GaN multiple quantum well solar cells with long operating wavelengths,” Appl. Phys. Lett. 94, 063505 (2009). R. Dahal, J. Li, K. Aryal, J. Y. Lin, and H. X. Jiang, "InGaN/GaN multiple quantum well concentrator solar cells," Appl. Phys. Lett. 97, 073115 (2010). B N. Pantha, J. Y. Lin, and H. X. Jiang, “III-nitride nanostructures for energy generation,” Proc. SPIE 7608, 76081I (2010). J. Li, J. Y. Lin, and H. X. Jiang, “Direct hydrogen gas generation by using InGaN epilayers as working electrodes,” Appl. Phys. Lett. 93, 162107 (2008). K. Aryal, B. N. Pantha, J. Li, J. Y. Lin, and H. X. Jiang, "Hydrogen generation by solar water splitting using p-InGaN photoelectrochemical cells," Appl. Phys. Lett. 96, 052110 (2010). R. Dahal, B. N. Pantha, J. Li, J. Y. Lin, and H. X. Jiang, “Realizing InGaN monolithic solar-photoelectrochemical cells for artificial photosynthesis,” Appl. Phys. Lett. 104, 143901 (2014)

Current trends in the design of Multi-Junction Solar Cells (MJSC) and quantum dot applications formthe backbone of the Concentrated Solar Photovoltaic (CSPs) Systems. There are a number ofdevelopments in solar power technology because of their improved power production, high efficiency,high absorption coefficients and cost-effectiveness. Selection of solar photovoltaic (PV) materials ofdifferent band gap energies to absorb complete solar spectrum is close to a reality with decrease in priceto performance ratio. This paper presents a generalized MJSC simulation model. The present modelassumes a mathematical approach, investigating solar cell characteristic curves including currentdensity (Jsc) and power (P) curves concerning the applied voltage for a different number of junctions andby varying the material properties of the multi-junction (MJ). The proposed model simulates differentparameters and performance characteristics of two different natures of MJSC includingInGaN/AlGaAs/InGaAs Triple Junction Solar Cell (TJSC) and InGaN/InGaN/AlInP/AlInP/AlGaAs/AlGaAs/AlGaAs Seven-Junction Solar Cell. Simulation results presented in this paper are in agreementwith experimental results. Solar cell parameters including short circuit current (Jsc), open circuit voltage(Voc), leakage current (Jo), output power (Pout) have also been calculated in this work. The efficiency(%𝜂) of a TJSC for visible light, ultraviolet (UV), visible and infrared (IR) light is presented. Theefficiency (%𝜂) of seven junction solar cell is calculated to be 63%. Characteristic curves of the solarcell are plotted as a function of voltage for different concentration levels and the number of junctions,which helps to design a solar power array that can operate to its peak power point. The objective of thisresearch is to improve the overall efficiency of MJSC.

APOLLONSOLAR’s NICE (New Industrial Solar Cell Encapsulation) technology makes use of an air and humidity tight sealing technology known from the insulating glass industry and based on the application of an organic sealing material from the family of poly-isobutylene (PIB). Important features of the NICE technology are the absence of EVA lamination and the use of an underpressure inside the module to provide the electrical series connexion between solar cell contact lines and metal interconnectors, thus suppressing the soldering of metal interconnectors to the solar cell busbars, which is the most widely used technology today. Other important features include a specially developed metal foil that is used as for the metal rear surface and new external connector which is integrated in the edge-sealing of the module. From a production point of view, the NICE module technology presents a largely simplify module assembling technology since it allows for a complete inline operation which can be fully automated. This paper presents first results obtained with the new NICE pilot production line, realised by VINCENT INDUSTRIES. The pilot line incorporates all necessary automated production stations without the automatic loading and sorting.

The paper made an extensive analysis of power generation in the territory of the Republic of Crimea. A special issue is the use of renewable energy sources (RES), in particular wind (WPP) and solar power plants (SPP). The current power generation capacities of the republic are determined and the power deficit is shown, which is currently covered by the electricity of the energy system of the Krasnodar Territory. One of the most important features of the development of the modern world is the increased attention of the world community to the problems of rationality and efficiency in the use of energy resources, the introduction of energy saving technologies and the search for renewable energy sources. In 2021, the countries of the Middle East and Europe increased the capacity of wind and solar power plants several times over. In India, installed renewable energy capacity has exceeded 100 GW. In June-July 2021, solar power generation in the European Union reached a record level and amounted to 39 TWh, an increase of 28%. For most European countries, renewable energy accounts for more than 15% of electricity generation in general. This is due to the fact that in the main markets, renewable, in particular solar electricity, is significantly cheaper than the energy of gas and diesel power plants.For Russia, the southern districts and coastal zones are effective geographical areas for the use of WPPs and SPPs. Thus, the Republic of Crimea is a geographically favorable place for the development of alternative energy.The technical and economic characteristics of SPP and WPP are determined, the current own wind and solar generation is considered in detail. The ways of development and permissible capacities of renewable energy sources in the Crimea are determined. According to the requirements for the systems of regulation, control and protection of renewable energy sources (RES) during their operation as part of the Unified Energy System of Russia, the use of alternative sources of electricity together with the main grid is permissible with their total capacity equal to 20% of the maximum load of the region. Therefore, the development and distribution of renewable energy in the Crimea has a huge potential. The applied systems for integrating RES into the overall energy system are considered, their shortcomings are identified.For the further development of RES in the Crimea, it is proposed to use a model of intelligent integration of SPPs and WPPs into the energy system of the peninsula using solid-state transformers. The use of power transformers for the transmission of electricity from RES to the network significantly reduces the flexibility of the system and eliminates the control of energy parameters. To increase the control capabilities of the output power to the network, as well as to reduce energy costs during voltage transformation, it is proposed to use solid-state transformers (SST) at the inverting stage. The use of SST changes the general principle of power transfer from RES to the network to the following: the DC voltage accumulated in the batteries of WPP and SPP is fed through a high-frequency inverter to a pulse transformer, where it rises to the voltage of the power line. Then it is rectified and inverted to the required mains frequency. Modern power semiconductor components may well provide such a model for integrating RES into the grid. The proposed model is distinguished by the presence of effective control of energy parameters, as well as high efficiency.