Thin-film Modules Research Articles

Optimization of a Molybdenum Oxide Bilayer Facilitating Hole Transfer in the p/i Interface for Transparent Thin-Film Silicon Solar Cells and Modules Using Laser Scribing

Optimization of a Molybdenum Oxide Bilayer Facilitating Hole Transfer in the p/i Interface for Transparent Thin-Film Silicon Solar Cells and Modules Using Laser Scribing

Development of a Photovoltaic-Based Module for Harvesting Solar Energy from Pavement: A Lab and Field Assessment

The concurrent worldwide energy crisis has become a strong incentive for researchers, governments, and industry professionals to focus on sustainable energy solutions. Consequently, pavement photovoltaic energy harvesting technologies, as one of the most common sustainable energy solutions, have recently seen a significant improvement, especially in the new innovative designs of pavement solar panels. In this study, an innovative design for a prototype energy harvesting system was proposed based on thin-film photovoltaic solar panels. In addition, the feasibility of utilizing the generated power of the proposed system to illuminate a pedestrian crosswalk to enhance the safety of an at-grade intersection was also analyzed. The designed prototype consists of a thin-film solar panel, a transparent cover to protect the solar panel, and a wooden frame to support the panel and distribute the load. Different materials for the transparent covering plates were investigated, including polycarbonate with varying thicknesses, textured GlassGrit, and textured float glass with corundum skid-resistant coating on the surface. Finite element analysis was also conducted to analyze the behavior of solar panel-incorporated layered asphalt pavement subjected to dynamic wheel loading. The results showed that the suggested model could sustain the structural loads of a moving wheel without failure. Experimental results of the study showed that considering the seven hours of operation on a typical sunny day, the proposed system could generate approximately 699 Watt-hour of power during 7 h of operation (9 a.m.–4 p.m.) from the 304.8 mm (12 inches) × 304.8 mm (12 inches) pavement solar panel.

Holistic yield modeling, top-down loss analysis, and efficiency potential study of thin-film solar modules

A holistic simulation of a photovoltaic system requires multiple physical levels - the optoelectronic behavior of the semiconductor devices, the conduction of the generated current, and the actual operating conditions, which rarely correspond to the standard testing conditions (STC) employed in product qualification. We present a holistic simulation approach for all thin-film photovoltaic module technologies that includes a transfer-matrix method, a drift-diffusion model to account for the p-n junction, and a quasi-three-dimensional finite-element Poisson solver to consider electrical transport. The evolved digital model enables bidirectional calculation from material parameters to non-STC energy yield and vice versa, as well as accurate predictions of module behavior, time-dependent top-down loss analyses and bottom-up sensitivity analyses. Simple input data like current-voltage curves and material parameters of semiconducting and transport layers enables fitting of otherwise less-defined values. The simulation is valuable for effective optimizations, but also for revealing values for difficult-to-measure parameters.

Electrochemical Fabrication and Characterization of Cu2ZnSnS4 (CZTS) Thin Film Deposits on Gold Substrate for Hydrogen Production

In this paper, room temperature one-step electrodeposition of chalcogenide CZTS followed by annealing at different temperatures was studied. The scanning electron microscopy images of the deposits confirmed the presence of agglomerated particles in the deposits. The deposits annealed at [Formula: see text]C did not show the presence of voids whereas deposits annealed at [Formula: see text]C showed severe sulfur loss and were off-stoichiometric. Annealing at [Formula: see text]C resulted in the deposits of compositions closer to the required ratio. Good absorbance over the entire visible range makes both the annealed deposits suitable absorber materials for thin-film photovoltaic cells. Current–voltage characteristics resulted in Ohmic trend and the slope of the plot increased with annealing temperature. The deposits showed good photosensitive behavior where resistance decreased upon shining the light source. The Mott–Schottky plot showed that the deposits were made of positively charged particles. CZTS thin film annealed at [Formula: see text]C provided higher H2 production rate (68.68 [Formula: see text]mol ⋅ [Formula: see text] ⋅ [Formula: see text], which was 32 times higher than that of CZTS annealed at [Formula: see text]C (2.08 [Formula: see text]mol ⋅ [Formula: see text] ⋅ [Formula: see text]. What’s more, photocatalytic activity of CZTS thin film remained 94% after 48 h which confirmed the good stability and reusability of CZTS thin film. CZTS thin film is a potential and durable candidate for photocatalysis.

Enhanced Mechanical Stability of CIGS Solar Module with Glass/Polyimide/Indium Tin Oxide for Potentially Flexible Applications

Cu(In,Ga)Se2 (CIGS) is a promising candidate for flexible photovoltaics because of its outstanding efficiency and flexibility. Despite its advantages, achieving high-efficiency CIGS solar cells on a flexible polyimide (PI) substrate is challenging as it requires a low-temperature process and relaxation of the thermal expansion. This limitation is critical in CIGS modules, particularly for monolithic interconnection processes by laser scribing. Furthermore, Mo back-contact (BC)-based PI cells are sensitive to each laser processing step. Laser scribing is one of the important processes in thin-film module manufacturing. In this study, for the first time, we applied indium tin oxide (ITO) instead of Mo as a BC layer on the spin-coated PI on soda-lime glass to obtain mechanically durable CIGS modules. The ITO BC-based module not only provides a crack-free CIGS layer but also offers superior device performance owing to the excellent laser scribing quality. Additionally, electrical properties related to respective scribing steps are analyzed in correlation with observed morphologies to evaluate parasitic resistance and optimize the laser scribing conditions. Consequently, a CIGS monolithic-integrated module with 15.03% efficiency at 40.14 cm2 (16.3% at 0.480 cm2) is fabricated on a novel “soda-lime glass/coated-PI/ITO structure”. We propose ITO BC-based cells as promising candidates for achieving high-efficiency and flexible CIGS solar modules.

A methodology to liberate critical metals in waste solar panel

The availability of critical metals is one of the driving factor to secure the transition of energy production to a renewable, low carbon one because of the material requirement in photovoltaic technology (PV), wind power generation and batteries. For example, precious metals are vital to manufacture crystalline silicon solar panel and tellurium, germanium, indium and gallium are essential in thin film photovoltaic panels. However, the pressure on the supply of critical metals increases with the growth of photovoltaics. Considering the resource availability, the recycling of critical metals from waste solar panels can enhance the sustainability of end-of-life management, although the recycled metal input is limited in present state. Among the recycling techniques, the separation and liberation of metals from non-metals are crucial. This study investigate a methodology to liberate thin film materials from copper indium gallium selenide (CIGS) thin-film solar panel to recycle photovoltaic material including indium and gallium via a mechanical process.An experimental technique using mineral processing techniques, crushing and grinding, are proposed to recycle critical metals from CIGS solar panel. In this study, the crushing experiments were conducted and the size based elemental distribution was analysed. The results showed crushing is capable to delaminate glass substrate and Fuerstenau upgrading curves and the ore separation degree were used to show that selective liberation occurs and the critical metals concentrate in coarse size fraction but may not be fully liberated. The morphology test using SEM-EDS to observe the surface of broken panel and the classification of broken particle based on size, metal concentration and surface morphology were conducted. The results suggested that approximately 90 w% of functional materials are still laminated on EVA in the size fraction larger greater than 2360 μm. It shows crushing alone will not fully liberate the material. Grinding can be used as a second stage recycling method, de-coating the target materials. The grinding test resulted in a more than 80 w% recovery rate of indium and the fine particle less than 38 μm contains more than 1500 ppm indium, more than 480 ppm gallium and 1500 ppm molybdenum. It could show that the combination of crushing and grinding is suitable to delaminate the panel and de-coat the critical metals to liberate and concentrate the metals.

Ultrasonic guided waves interaction with cracks in the front glass of thin-film solar photovoltaic module

Ultrasonic guided waves interaction with cracks in the front glass of thin-film solar photovoltaic module

Photovoltaics literature survey (no. 182)

Photovoltaics literature survey (no. 182)

Machine learning and analytical model hybridization to assess the impact of climate change on solar PV energy production

The United Nations' (UN) Sustainable Development Goals (SDGs) agenda has triggered numerous countries to harness solar energy from solar photovoltaic (PV) modules to increase the share of renewable energy in the global energy mix. However, geographical and climatic factors have a significant impact on the electrical performance of solar PV modules. In addition, since solar PV energy production models are the only physics-based approach to transferring ground-measured PV energy production to other locations, the authors developed 294 physical models from six different PV power technologies and validated them for the model's adaptability. To facilitate the possible determination of PV electric energy generation in the unique geographical and climatic environment of the experiment site, these models were built using machine learning, Gumbel's probabilistic approach (GPM), and hybridization of the two. The major challenges in this study are in developing the hybridized machine learning with the Gumbel probabilistic functional model, which resides in the mathematical transformation process, which required a great deal of repeated mathematical science knowledge to arrive at the final transformed and efficient model for predicting the potential of solar PV output. With a thorough coefficient of determination (R2) of 0.9998% and a root mean square error (RMSE) of 0.0063 kwh, the hybrid model with only the measurable solar radiation parameter is the closest to the measured PV energy production of all technologies. The best hybridized model was used to explore the potential impacts of climate change on the different solar PV technologies. This was achieved by using energy parameters from the Australian Community Climate and Global System Simulation (ACCESS-CM2) in Phase 6. On an annual basis, the effects of climate change on various PV technologies have had a small adverse impact (less than 1%) on these renewable energy technologies. It was also found that, compared to other technologies, CIGS thin film technology produced the least negative effects on climate change, with 10.94%–36.75% in the best-case, 35.71%–36.36% in the moderate-case, and 33.33–40.00% in the worst-case scenario for shared socioeconomic pathways (SSP126, SSP245, and SSP585) emissions. This suggests the intrinsic properties of Copper Indium Gallium Selenide (CIGS) thin film modules are more effective at withstanding high temperatures as they contribute 60.00–89.66% of their intrinsic module properties to PV energy production compared to other technologies. However, taking into account the time, resource availability, cost-effectiveness, commercialization, and consumption of various PV technologies studied in this era of global sustainability, poly-crystalline (p-Si) technology is highly recommended for harvesting solar PV energy products in Alice Springs, Australia.

Reducing Nonradiative Losses in Perovskite LEDs through Atomic Layer Deposition of Al2O3 on the Hole-Injection Contact.

Halide perovskite light-emitting diodes (PeLEDs) exhibit great potential for use in next-generation display technologies. However, scale-up will be challenging due to the requirement of very thin transport layers for high efficiencies, which often present spatial inhomogeneities from improper wetting and drying during solution processing. Here, we show how a thin Al2O3 layer grown by atomic layer deposition can be used to preferentially cover regions of imperfect hole transport layer deposition and form an intermixed composite with the organic transport layer, allowing hole conduction and injection to persist through the organic hole transporter. This has the dual effect of reducing nonradiative recombination at the heterojunction and improving carrier selectivity, which we infer to be due to the inhibition of direct contact between the indium tin oxide and perovskite layers. We observe an immediate improvement in electroluminescent external quantum efficiency in our p-i-n LEDs from an average of 9.8% to 13.5%, with a champion efficiency of 15.0%. The technique uses industrially available equipment and can readily be scaled up to larger areas and incorporated in other applications such as thin-film photovoltaic cells.

Application of non-contact electrostatic voltmeter to identify underperforming modules in grid-connected photovoltaic systems

This paper presents a technique that uses maximum power point voltage (Vmpp) to quantitatively identify the underperformance photovoltaic (PV) modules in grid-connected PV systems using a non-contact Electrostatic Voltmeter (ESV). Unlike the other existing techniques, this technique doesn't require the module's disconnection from the grid or other modules in a string. First, in this work, the ESV was tested for the application of thin film modules (off-grid and on-grid), and a comparison of the ESV sensed voltages with the voltmeter voltage values indicated a difference of less than 2%. Second, the least power-producing module was identified by the IV curves analysis and the Vmpp technique, and the results were compared. The comparison of both characterization tools quantitatively pointed out to the same module as the lowest performance module. It is a contactless, time and cost-saving method and is useful for quantitatively determining defective and poor-performing PV modules in large power plants where continuity of the energy production is preferred during the testing.

Simulation and Numerical Investigation of the Effect of Temperature and Defect on ZnTe/ZnSe/ZnO Thin-Film Photovoltaic Solar Cell Performance Efficiency

Thin film-based solar cell semiconductor emerges as a promising candidate for solar photovoltaic future applications. A proposed heterojunction ZnTe/ZnSe/ZnO thin film-based solar cell has been simulated by using Solar Cell Capacitance Simulator-One Dimension (SCAPS-1D) in order to study the impact of temperature and defect layers on its efficiency parameters. The heterojunction thin film-based solar cell has been selected for simulation due to its low cost, availability, and reduced toxicity compared to other absorber layer materials. Numerical modeling has been used to comprehend device properties before fabrication. The results indicate that the efficiency parameters (Jsc, VOC, FF, and η) have been significantly affected by temperature and the presence of defect layers. The simulated J-V characteristics demonstrate how defect density affects solar cell efficiency parameters. In the defect system, the efficacy parameters have been reduced except for a slight increase in VOC at 300 K. The findings of this study are significant as they demonstrate the importance of understanding the impact of temperature and defect layers on the performance of thin film-based solar cells. The use of numerical modeling tools like SCAPS-1D can aid in the design and development of new solar cell technologies, which could ultimately lead to the widespread adoption of solar energy as a clean and sustainable energy source.

Fault Detection and Classification of CIGS Thin-Film PV Modules Using an Adaptive Neuro-Fuzzy Inference Scheme.

The use of artificial intelligence to automate PV module fault detection, diagnosis, and classification processes has gained interest for PV solar plants maintenance planning and reduction in expensive inspection and shutdown periods. The present article reports on the development of an adaptive neuro-fuzzy inference system (ANFIS) for PV fault classification based on statistical and mathematical features extracted from outdoor infrared thermography (IRT) and I-V measurements of thin-film PV modules. The selection of the membership function is shown to be essential to obtain a high classifier performance. Principal components analysis (PCA) is used to reduce the dimensions to speed up the classification process. For each type of fault, effective features that are highly correlated to the PV module's operating power ratio are identified. Evaluation of the proposed methodology, based on datasets gathered from a typical PV plant, reveals that features extraction methods based on mathematical parameters and I-V measurements provide a 100% classification accuracy. On the other hand, features extraction based on statistical factors provides 83.33% accuracy. A novel technique is proposed for developing a correlation matrix between the PV operating power ratio and the effective features extracted online from infrared thermal images. This eliminates the need for offline I-V measurements to estimate the operating power ratio of PV modules.

Lowering Cost Approach for CIGS-Based Solar Cell Through Optimizing Band Gap Profile and Doping of Stacked Active Layers-SCAPS Modeling.

In this research article, we carry out investigation on compensating the efficiency loss in thin-film CIGS photovoltaic (PV) cell due to absorber coat depth reduction. We demonstrate that the efficiency loss is mainly caused by the disruption of the charge-carrier transport. We propose an architecture engineered with a stepped band gap profile for improving the efficiency of charge-carrier transport and collection. By modifying the gallium content, we tuned the band gap profile of the active layer of a reference experimental cell from which we previously collected all parameters. Using the simulator environment SCAPS-1D, we modeled a three-steps stacking profile of active layer with different gallium contents from one layer to another. Based on the results obtained, the band gap configuration herein proposed appears to be a prospective strategy for high-performance ultrathin Cu(In,Ga)Se2-based PV cell architecture engineering. By combining this approach with the optimization of the active layer doping, we enhanced the yields of the reference structure from 18.93% for a 2 μm active layer to 23.36% for only 0.5 μm thickness of active layer, that is, an enhancement of 4.4%. The fill factor increased from 73.24 to 81.73%, that is, an additional stability indicator value of 8.5%. The good values of the obtained efficiency and the improvement of the fill factor value are relevant indicators of a stable device. Active layer stacking combined with a stepped band gap profile and doping level optimization is definitely providing new perspectives in thin-film CIGS high-performance PV cell achievement.

Roadway Embedded Smart Illumination Charging System for Electric Vehicles

Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways, such as mechanical pressure, this study presents the development and implementation of an innovative charging technique for electric vehicles (EVs) by fully utilizing the existing roadways and state-of-the-art nanotechnology and power electronics. The developed Smart Illuminative Charging is a novel wireless charging system that uses LEDs powered by piezoelectric materials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle’s battery. The piezoelectric materials were tested for their mechanical-to-electrical energy conversion capabilities and the relatively large-area EH2N samples (2 cm × 2 cm) produced high output voltages of up to 52 mV upon mechanical pressure. Furthermore, a lab-scale prototype device was developed to testify the proposed mechanism of illuminative charging (i.e., “light” coupled pavement and vehicle as a wireless energy transfer medium).

Development and application of graphene silk solar panel concept in smart bus stop design

With the continuous growth of the population, with the expansion of the urban area. Human activities and behavior are depleting limited resources, a large number of these private vehicles occupy our roads, it also causes various environmental problems. With the increasing awareness of environmental protection, the way of green travel has gradually become the way of travel advocated by people who living in the metropolis. Convenience and environmental protection are a major advantage of public transport, but unfortunately, the functions, services and environment of many bus stops are not convenient and friendly; Therefore, the smart bus stop was born, it can not only provide real-time bus information, but also provide a safe and comfortable waiting space. However, with the upgrading of service functions, the problem of energy consumption has become increasingly prominent. Powering through solar panels can naturally provide a sustainable energy source for smart bus stops, but many studies have found that solar panels themselves are not environmentally friendly, regardless of their materials and recyclability. The author’s investigation found that relevant studies have confirmed that spraying an aqueous solution containing carbon nanotubes or graphene on mulberry leaves for feeding silkworms doubles the toughness of the silk spit, and the conductivity of carbonized silk is 10 times higher. In addition, the robotic fiber spinning technology will allow silkworms to independently complete the production of silk objects without killing the silkworms. Through the research on graphene silk materials and robotic fiber spinning technology, this paper proposes a biologically autonomous solution to the production of graphene silk thin-film solar panels, so as to seek to solve the pollution problem of solar panels in the smart stop.

ELECTRICAL PERFORMANCE EVALUATION OF PHOTOVOLTAIC TETHER SAMPLES FOR DEORBIT APPLICATIONS

When it comes to deorbiting spacecraft at their end of life to avoid future space debris, electrodynamic tethers (ET) are promising, offering fully propellantless operation. However, generating thrust or drag requires the ET to close the electric circuit with the surrounding plasma environment with a cathode, which to date still requires an external power source and, in some cases, expellant. To achieve full autonomy and high performances, the bare-photovoltaic tether (BPT) concept was proposed, which aims to use the surface area of the ET to harvest solar power by applying thin-film photovoltaic cells on top. The generated power may be sufficient to enable consumable-less cathodes, making the overall concept attractive. Different design configurations for BPTs are presented alongside the major challenges of the concept. An overview of the electrical performance and power capabilities of a photovoltaic tether segment is given.

Industrial scale thin-film composite membrane modules for salinity-gradient energy harvesting through pressure retarded osmosis

The current work highlights development of novel thin-film composite hollow fiber membranes for pressure retarded osmosis applications to harvest salinity gradient energy. The membranes were developed with a specific target of harnessing the salinity gradient energy between wastewater reverse osmosis retentate and seawater reverse osmosis brine via osmotic mixing. The hollow fiber membranes were prepared by coating a polyethersulfone substrate with a thin-film composite polyamide layer via interfacial polymerization, which were assembled into modules of different diameters for lab scale and pilot scale evaluation. As the module size increased from 1-in. to 2-in., and 4-in., the water permeability, tested against a 1000 mg/L sodium chloride solution at 15 bar, decreased from 2.6 L m−2 h−1 bar−1 to 2.0 L m−2 h−1 bar−1, and 1.2 L m−2 h−1 bar−1, respectively. The power density, measured in the lab-scale unit using 1 M sodium chloride draw solution, and DI water feed solution, also decreased from 9.1 W/m2 to 5.3 W/m2 with increasing module size. Pilot scale evaluation of the 4-and 8-in. modules on a 24 m3/day unit resulted in lower power densities of 2.5 W/m2 and 1.5 W/m2 which translated to 0.024 kWh/m3 and 0.05 kWh/m3 of salinity-gradient energy harvested, respectively.

Techno-environmental Simulations for Solar Energy-Powered Seawater Reverse Osmosis Desalination for a Hyper Arid Coastal Region

This study investigates the efficiency of a solar-powered seawater desalination plant (DP) using reverse osmosis for an arid coastal region. The solar models are investigated using local meteorological data, including direct, diffused and global irradiance. The meteorological data are obtained using local typical meteorological data set collected from a ground weather station. The PVsyst simulation tool is used to model a grid-connected solar PV system utilizing three photovoltaic (PV) technologies: thin-film, monocrystalline, and polycrystalline. Three scenarios were considered: restricted area, daily water production and design capacity. The optimum configuration for the restricted area scenario at the seawater DP location considered is an on-grid thin-film module (170 W) with a tilt angle of 20° and an inverter unit of 2000 kW. The solution module area is 15,248 m2. The annual electricity production will be approximately 4251.1 MWh/y, which represents only 3.1% of the DP demand. Thin-films produce higher annual electricity than monocrystalline and polycrystalline silicon by 8.3% and 5.9%, respectively, but require 15.9% and 5.7% more space than monocrystalline and polycrystalline silicon, respectively. For Shuwaikh DP, a 30 MIGD DP will require a PV system with a capacity of 120 MWp at 30° tilt angles and 60 inverters. The design environmental impact was assessed using life cycle assessment (LCA). The carbon footprint will decrease from 7.3 x10-5 to 1.8 x10-5 (kg CO2 equivalent), for the 30 MIGD production. The fossil fuel depletion will decrease by approximately 80%. However, the large number of solar panels and the significant total ground area required for the 30 MIGD. The solar array of 1,531,054 m2 will adversely affect the urban land occupation impact category by 84% and will increase metal depletion by 37%.The response surface optimization indicates that the optimal performance in the coastal region for power desalination plants is achieved when using a thin-film at a tilt angle of 20 o.

Influence of absorption, energy band alignment, electric field, recombination, layer thickness, doping concentration, temperature, reflection and defect densities on MAGeI3 perovskite solar cells with Kesterite HTLs

Over the past decade, perovskite materials have emerged as a promising absorber layer in photo voltaic (PV) cells. Germanium (Ge) based perovskite layers have attracted the attention of scientists because of its excellent photovoltaic properties and nontoxic nature. Selecting the right material for charge transport layers (CTL) can further enhance the performance and stability of the cell. Kesterite materials are chalcogenides quaternary compound with high conductivity and tunable bandgap. They have exhibited excellent performance when employed in thin film PV cells as the active material and hence emerged as an option to be used as hole transport layer (HTL) in perovskite solar cells. In this work the Ge based perovskite solar cell (PSC) of methyl ammonium germanium tri-iodide (MAGeI3) is numerically modelled with 6 kesterite quaternary compounds as HTLs and 4 oxide/sulphide materials as electron transport layers (ETL). Henceforth, a total of 24 unique structures are numerically modelled and optimized using SCAPS-1D. A systematic methodology is adopted to analyze the effect of the charge transport materials on the absorption, quantum efficiency, energy band alignment, electric field intensity, recombination rate, carrier density, thickness, doping concentration, temperature, reflection and interface defect densities of the PSC in detail. The optimization of the PSC structures enhanced the performance of the cells up to 7% more. Based on the simulation results the best performing perovskite structures were TiO2/Per/CZTS and SnO2/Per/CZTS with PCE of 24.57% and 24.87%, Jsc of 16.13 mA cm−2 and 16.32 mA cm−2, Voc of 1.730 V and 1.733 V and F.F of 88.10% and 88.101% respectively.