Polycrystalline Silicon Solar Cells Research Articles

Optimizing feature extraction and fusion for high-resolution defect detection in solar cells

In this paper, we propose a novel architecture for defect detection in electroluminescent images of polycrystalline silicon solar cells, addressing the challenges posed by subtle and dispersed defects. Our model, based on a modified Swin Transformer, incorporates key innovations that enhance feature extraction and fusion. We replace the conventional self-attention mechanism with a novel group self-attention mechanism, increasing the mAP50:5:95 score from 50.12 % to 52.98 % while reducing inference time from 74 ms to 62 ms. We also introduce a spatial displacement with shift convolution module, replacing the traditional Multi-Layer Perceptron, which further enhances the model's receptive field and improves precision and recall. Additionally, our fast multi-scale feature fusion mechanism effectively combines high-resolution details with high-level semantic features from different network layers, optimizing defect detection accuracy. Experimental results on the PVEL-AD dataset demonstrate that our model achieves the highest mAP50 score of 83.11 % and an F1-Score of 84.33 %, surpassing state-of-the-art models while maintaining a competitive inference time of 66.3 ms. These findings highlight the effectiveness of our innovations in improving defect detection accuracy and computational efficiency, making our model a robust solution for quality assurance in solar cell manufacturing.

Deep learning-based method for defect detection in electroluminescent images of polycrystalline silicon solar cells

To achieve defect detection in bare polycrystalline silicon solar cells under electroluminescence (EL) conditions, we have proposed ASDD-Net, a deep learning algorithm evaluated offline on EL images. The model integrates strategies such as downsampling adjustment, feature fusion optimization, and detection head improvement. The ASDD-Net utilizes the Space to Depth (SPD) module to effectively extract edge and fine-grained information. The proposed Enhanced Cross-Stage Partial Network Fusion (EC2f) and Hybrid Attention CSP Net (HAC3) modules are placed at different positions to enhance feature extraction capability and improve feature fusion effects, thereby enhancing the model's ability to perceive defects of different sizes and shapes. Furthermore, placing the MobileViT_CA module before the second detection head balances global and local information perception, further enhancing the performance of the detection heads. The experimental results show that the ASDD-Net model achieves a mAP value of 88.81% on the publicly available PVEL-AD dataset, and the detection performance is better than the current SOTA model. The experimental results on the ELPV and NEU-DET datasets verify that the model has some generalization ability. Moreover, the proposed model achieves a processing frame rate of 69 frames per second, meeting the real-time defect detection requirements for solar cell surface defects.

Hydrophobic and Luminescent Polydimethylsiloxane PDMS-Y2O3:Eu3+ Coating for Power Enhancement and UV Protection of Si Solar Cells.

Solar cells have been developed as a highly efficient source of alternative energy, collecting photons from sunlight and turning them into electricity. On the other hand, ultraviolet (UV) radiation has a substantial impact on solar cells by damaging their active layers and, as a result, lowering their efficiency. Potential solutions include the blocking of UV light (which can reduce the power output of solar cells) or converting UV photons into visible light using down-conversion optical materials. In this work, we propose a novel hydrophobic coating based on a polydimethylsiloxane (PDMS) layer with embedded red emitting Y2O3:Eu3+ (quantum yield = 78.3%) particles for UV radiation screening and conversion purposes. The favorable features of the PDMS-Y2O3:Eu3+ coating were examined using commercially available polycrystalline silicon solar cells, resulting in a notable increase in the power conversion efficiency (PCE) by ~9.23%. The chemical and UV stability of the developed coatings were assessed by exposing them to various chemical conditions and UV irradiation. It was found that the developed coating can endure tough environmental conditions, making it potentially useful as a UV-protective, water-repellent, and efficiency-enhancing coating for solar cells.

Mussel-Inspired Self-Adhesive and Tough Hydrogels for Effectively Cooling Solar Cells and Thermoelectric Generators.

Adhesive hydrogel-based evaporative cooling, which necessitates no electricity input, holds promise for reducing energy consumption in thermal management. Herein, inspired by the surface attachment of mussel adhesive proteins via abundant dynamic covalent bonds and noncovalent interactions, we propose a facile strategy to fabricate a self-adhesive cooling hydrogel (Li-AA-TA-PAM) using a copolymer of acrylamide (AM) and acrylic acid (AA) as the primary framework. The monomers formed hydrogen bonds between their carboxyl and amide groups, while tannic acid (TA), rich in catechol groups, enhances the adhesion of the hydrogel through hydrogen bonding. The hydrogel demonstrated strong adhesion to various material surfaces, including plastic, ceramic, glass, and metal. Even under high-speed rotation, it still maintains robust adhesion. The adhesion strength of the Li-AA-TA-PAM hydrogel to aluminum foil reached an impressive value of 296.875 kPa. Interestingly, the excellent contact caused by robust adhesion accelerates heat transfer, resulting in a rapid cooling performance, which mimics the perspiration of mammals. Lithium bromide (LiBr) with hydroactively sorptive sites is introduced to enhance sorption kinetics, thereby extending the effective cooling period. Consequently, the operation temperature of commercial polycrystalline silicon solar cells was reduced by 16 °C under an illumination of 1 kW m-2, and the corresponding efficiency of energy conversion was increased by 1.14%, thereby enhancing the output properties and life span of solar cells. The strategy demonstrates the potential for refrigeration applications using viscous gels.

Effect of concentration of Er3+ on up-conversion luminescence in NaYF4 embedded oxy-fluoride glass-ceramics under 1550 nm excitation

Oxy-fluoride glass-ceramics (GC) has advantages such as low phonon energy of fluorides and the excellent physical and chemical properties of oxides. Here we report the synthesis of a series of transparent oxy-fluoride GCs with various doping contents of Er3+ (0.2 mol%-10 mol%) synthesized under different temperatures, and their UCL properties under the excitation of 1550 nm laser. We found that Er3+-doped glass matrix with NaYF4 fluoride nanocrystals demonstrated greatly enhanced UCL compared with as-prepared glass. The samples showed red light emission with 3 mol% Er3+ as the optimal doping content. The wavelength of UCL could be fine-tuned by the temperature of heat treatment, and 893 K seems to be the optimal temperature. We also studied the photoelectric conversion characteristics of the optimal Er3+ doped oxy-fluoride GCs with a polycrystalline silicon solar cell under the excitation of a 1550 nm laser as a possible strategy to effectively improve the photo-electric conversion efficiency of solar cells.

Measurement of the Current-Voltage Curve of Photovoltaic Cells Based on a DAQ and Python

The renewable energy has grown extensively in the last decades. The photovoltaic panels have been playing a significant role in the technologies used to produce this kind of energy. This tendency is expected to continue in the future, because the cost of the solar panels has been gradually reduced. Systems providing information of the performance of the solar cells can be helpful for technicians and researchers. In this paper a system to measure the I-V curves of photovoltaic cells is presented. This is composed by a data acquisition board (DAQ) and a personal computer (PC). The program to control the DAQ is written in Python. With this system a polycrystalline silicon solar cell was tested under low irradiance conditions (less than 100 W/m2) with an artificial light source. The repeatability of the I-V curves obtained has less than 5 % error.

Efficiency Enhancement in Photovoltaic–Thermoelectric Hybrid Systems through Cooling Strategies

The integration of photovoltaic (PV) and thermoelectric (TE) modules in PV-TE systems has shown potential for expanding the utilization of the solar spectrum, enhancing the total power output, and reducing the space that is required for PV power plants. This paper discusses the characteristics of a practical PV-TE system model. Typically, to boost the power output of the TE component, a significant temperature difference is induced across the thermoelectric generator (TEG) module using various heat removal methods. These cooling techniques not only enhance the TEG module’s efficiency but may also improve the performance of the PV component. In this study, we evaluate the efficiencies of PV-TE systems that are equipped with polycrystalline silicon solar cells and seven distinct TEGs under four different conditions. Initially, the PV-TE hybrid systems are tested without a cooling mechanism at an ambient temperature of 25 °C (Standard Test Conditions EN/IEC 61215). Subsequently, we examine the systems with a passive cooling approach, employing aluminum heat sinks to facilitate improved heat dissipation. Further tests involve an active cooling system using water and then nanofluid as coolants. The results from these assessments aim to establish a benchmark for enhancing the efficiency of future PV-TE systems.

Surface engineering of Sio2-Zro2 films for augmenting power conversion efficiency performance of silicon solar cells

Improving solar cell performance hinges significantly on the application of anti-reflective surface coatings. A wide variety of coating techniques, including blade coating, spin coating, dip coating, and others were employed. The present research investigation employed various coating materials, namely SiO2 (Silicon dioxide), ZrO2 (Zirconium dioxide), and SiO2–ZrO2 blends, to apply a protective layer onto polycrystalline silicon solar cells using the sputter coating process. The efficiency of these solar cells with multilayer coating was assessed through diverse characterization methods. The uniform thin films were obtained using a 45-min coating process using an input voltage source of 17 kV, which was confirmed through analyses conducted using FESEM and AFM techniques. The UV–Vis spectroscopy and current-voltage source metre were employed to examine the light absorption and transmittance of bare and coated silicon solar cells. When compared to alternative solar cells, the solar cell coated with a combination of SiO2 and ZrO2 demonstrated uniform deposition and a low light reflectance of only 6 %. SiO2–ZrO2 gains a highest power conversion efficiency (PCE) of 17.6 % under controlled light source. This superior performance was due to the increase in photon transmittance in to the depletion region. Furthermore, the electrical resistivity of the SiO2–ZrO2 blend coated solar cell was measured using the four-probe method was found to be 2.89 × 10−3 Ω-cm, which was lower than that of other solar cells. From the experimental results, it was clear that SiO2 - ZrO2 blend-coated solar cells outperformed both other coated and uncoated solar cells. Consequently, SiO2–ZrO2 blends emerged as superior anti-reflective materials for achieving peak performance.

Thermal behavior of parasitic resistances of polycrystalline silicon solar cells

In this work, we investigate the influence of temperature on the series and shunt resistances of polycrystalline silicon solar cells and then to determine the specific expressions of both parasitic resistances as function of temperature. We have exploited the current-voltage characteristics of polycrystalline silicon solar cell at different temperatures and under constant illumination (1000 W/m2). The obtained results show that the series resistance, Rs , is a positive temperature coefficient type; however, the shunt resistance, Rsh , is a negative temperature coefficient type.

Towards 30% Efficiency by 2030 of Eco-Designed Building Integrated Photovoltaics

The necessity of affordable and durable building-integrated photovoltaics has gained widespread importance for the renewable energy transition involving electrification and decarbonization in climate-neutral cities that possess many public health co-benefits. Although the PV market is dominated by polycrystalline and monocrystalline silicon solar cells of the first generation, there is an impetus in the research lately for more sophisticated solar cell architectures with higher efficiency, longer lifetime, and less use of raw materials in an eco-design approach. To accelerate building integration of the next generation of photovoltaics and the associated climate change mitigation benefits, we propose in this work a holistic novel approach to the requirements and associated parameters for the emerging and innovative PV structures, spanning from intrinsic cell properties to panels effect in the urban environment. Within this framework, and supported by building simulation, the improvement of cells’ efficiency is revealed as an important parameter for their wider PV building and urban deployment as well as a major improvement in covering the building energy needs with minimized thermal impact in the urban environment. By analyzing the lab-reported values and the timeline of emerging and novel tandem solar cells, we propose the 30% BIPV efficiency of the eco-designed BIPV products as a central milestone to be attained before 2030 for a sustainable urban transformation.

Effect Of Zinc Oxide—Aluminium Oxide Mechanical Blends for Boosting the Polycrystalline Silicon Solar Cell Performance through Antireflection Properties

Effect Of Zinc Oxide—Aluminium Oxide Mechanical Blends for Boosting the Polycrystalline Silicon Solar Cell Performance through Antireflection Properties

Mpact of laser surface modification on polycrystalline silicon photovoltaic cell by means of CO2 laser

In this research, we investigate the effect of laser texturing on the photo-electrical properties of the polycrystalline silicon solar cell. Laser surface texturing technique was used to achieve the texturing results, which based on the interaction between pulsed CO2 laser (10.6μm) and polycrystalline silicon used for solar cells. Four of photovoltaic solar cells have been textured in two dimensions in different ranges (1 cm x 1cm and 2 cm x 2 cm) with different line spacing. Solar cells with laser-modified surface were characterized by SEM as well as photo-electrically before and after texturing process. The obtained results showed that laser surface texturing with small grooves spacing, results in increasing of the melted silicon surface area which enhance the silicon electrical properties. Furthermore, it increases the optical path length inside the solar cell which enhances light trapping.

Hybrid high-concentration photovoltaic system designed for different weather conditions

In this study, we propose a novel high-concentration photovoltaic (HCPV) cell by considering both the light leakage characteristics of the Fresnel-lens-based solar cell modules and the performance issues arising from cloud shading in practical use. We use our self-constructed systems to conduct field measurements for up to half a year under various environmental conditions. According to the acquired results, it was surprising to know that in the area other than the focusing area, the so-called light leakage region, there always bears illuminance of about 20,000–40,000 lx whether it is a sunny day or a cloudy day with different cloud conditions. Such an interesting result is caused by the light scattering of the clouds and the inherent leakage characteristic of a Fresnel lens. To prove this important finding, we simulated the illuminance of the Fresnel lens structure used in the measurement with apertures of different sizes to determine the detected area. In the laboratory, the diffuse plates were used to mimic the situation of varying cloud layer thicknesses. The trend of calculated and measured results fitted well with the field measurements. Also, the experimental and simulation results show that the round angle and draft facet of the Fresnel lens were responsible for light leakage. This finding prompted us to propose a hybrid high-concentration solar module in which more cost-effective polycrystalline silicon solar cells are placed around the high-efficiency wafer of HCPV to capture the dissipated light leakage and convert it into usable electricity.

Biomass-based carbon quantum dots for polycrystalline silicon solar cells with enhanced photovoltaic performance

Polycrystalline silicon solar cells modified using biomass resources are promising candidates to accomplish the goal of carbon neutrality. Developing a device with high power conversion efficiency (PCE) is important to resolve the ever-increasing energy shortage issues. Therefore, we develop a facile solution-casting approach to synthesise ethylene-vinyl acetate (EVA) films modified with ultra-high fluorescent carbon quantum dots (CQDs). The films were coated on the surface of polycrystalline silicon solar cells and the PCE increased from 13.19% to 13.65%. The ultra-high fluorescent CQDs were prepared from Ginkgo biloba via a hydrothermal process, and different parts of Ginkgo biloba-based CQDs were investigated in various conditions. The ultra-high fluorescent CQDs obtained at 180 °C, 8 h and a reaction concentration of 0.048 g/mL from Ginkgo wood resulted in high fluorescence of up to 976.74 a.u.. At an excitation wavelength of 365 nm. This work substantially expands the potential of EVA films containing ultra-high fluorescent CQDs for applications in the photovoltaic, environment and energy fields.

Analysis of Super-Solar Integrated Patch Antenna for Sub-6 GHz and Beyond 6 GHz Millimeter Wave 5G Applications

This article describes a new compact parasitic patch-loaded transparent patch antenna with a copper ground plane for wireless-fidelity (Wi-Fi) and 5thgeneration (5G) millimeter-wave (mm-wave) applications. The proposed antenna uses two rectangular parasitic patches with a rectangular main radiation patch. The L-shaped strips are also added to the main radiation patch and one of the rectangular parasitic patches to cover both the sub-6 GHz and beyond 6 GHz mm-wave 5G frequency spectrums. The same transparent patch antenna with a solar ground plane is built, and its effect is parametrically studied alongside the integration of a polycrystalline silicon solar cell. The proposed antennas with a dimension of 42x30x2 mm23 are fabricated and experimentally validated for impedance and radiation characteristics. In terms of impedance bandwidth, the proposed copper ground plane antenna offers 36.89% (5.04-7.32 GHz), 5.15% (14.35-15.11 GHz), 6.23% (27.08-28.79 GHz), and 21.34% (31.64-39.81 GHz). The solar cell serves as both a photovoltaic generator and the ground plane of the transparent antenna. The same radiating patch with a solar ground plane offers impedance bandwidth of 36.03% (4.47-6.56 GHz), 14.4% (9.6-11.12 GHz), 2.55% (22.14-22.71 GHz), and 27.9% (28.79-39.05 GHz) for 5G applications.

Review: Heterojunction Tandem Solar Cells on Si-Based Metal Oxides

PV technology offers a sustainable solution to the increased energy demand especially based on mono- and polycrystalline silicon solar cells. The most recent years have allowed the successful development of perovskite and tandem heterojunction Si-based solar cells with energy conversion efficiency over 28%. The metal oxide heterojunction tandem solar cells have a great potential application in the future photovoltaic field. Cu2O (band gap of 2.07 eV) and ZnO (band gap of 3.3 eV) are very good materials for solar cells and their features completely justify the high interest for the research of tandem heterojunction based on them. This review article analyzes high-efficiency silicon-based tandem heterojunction solar cells (HTSCs) with metal oxides. It is structured on six chapters dedicated to four main issues: (1) fabrication techniques and device architecture; (2) characterization of Cu2O and ZnO layers; (3) numerical modelling of Cu2O/ZnO HTSC; (4) stability and reliability approach. The device architecture establishes that the HTSC is constituted from two sub-cells: ZnO/Cu2O and c-Si. The four terminal tandem solar cells contribute to the increased current density and conversion efficiency. Cu2O and ZnO materials are defined as promising candidates for high-efficiency solar devices due to the morphological, structural, and optical characterization emphasized. Based on multiscale modelling of PV technology, the electrical and optical numerical modelling of the two sub-cells of HTSC are presented. At the same time, the thermal stability and reliability approach are essential and needed for an optimum operation of HTSC, concerning the cell lifetime and degradation degree. Further progress on flexible HTSC could determine that such advanced solar devices would become commercially sustainable in the near future.

Influence of the Wavelength on the Series and Shunt Resistances of a Polycrystalline Silicon Solar Cell n+-p-p+ in Frequency Modulation

<p>A study of the illumination wavelength effect on the series and shunt resistances of a serial vertical junction silicon solar cell in frequency modulation is done. From the continuity equation of the minority carriers’ density, the expressions of the minority carriers’ density, the photocurrent density, and the photovoltage, are determined. The curves of the I-V characteristic permit us to deduce the series and shunt resistances, which depend on the wavelength and frequency modulation. A few values of series and shunt resistances in short and long wavelengths are determined respectively at the open circuit and the short circuit situation.</p>

Synthesis, structural, and optical properties of (Ag/ZnS) core–shell nanostructures and their applications to polycrystalline silicon solar cells

The present work focuses on the two-step chemical synthesis of Ag/ZnS nanoparticles as core–shell nanoparticles. Various techniques were used to characterize nanoparticles, including UV–Vis spectroscopy, Dynamic Light Scattering, Transmission Electron Microscopy, Fourier Transform Infrared Spectroscopy, and a Solar Simulator. UV–Vis spectral analysis of Ag/ZnS core–shell nanoparticles at 450, 469, and 498 nm reveals broad plasmon resonance bands. The solution of silver nanoparticles was redshifted by increasing its concentration. Core and shell images obtained from each nanoparticle show different contrasts, indicating that the core and shell materials differ. Infrared spectroscopy confirmed the presence of ZnS NPs around AgNPs. Incorporating Ag/ZnS into polycrystalline silicon solar cells has improved efficiency from 13.02 to 14.29%.

Effect of Molybdenum Disulphide Thin Films on Enhancing the Performance of Polycrystalline Silicon Solar Cells

This research work focuses on augmenting the power conversion efficiency of the polycrystalline silicon solar cell with the aid of antireflection coating (ARC) of synthesized molybdenum disulphide (MoS2). The sol-gel technique and electrospraying method were preferred for synthesizing and depositing MoS2 as transparent thin films on the surface of the solar cells. The optical, electrical, structural, and thermal properties of the coated solar cells were analyzed for understanding the influence of the MoS2 coating. Five different samples (A-II, A-III, A-IV, A-V, and A-VI) were coated with varying coating time. Among them, 120 min coated sample experienced a maximum power conversion efficiency (PCE) of 17.96% and 18.82% under direct sunlight and neodymium light with resistivity as low as 2.79 × 10 − 3 Ω − cm . The investigation of optical properties of the coated solar cells revealed a maximum transmittance of 93.6% and minimum reflectance of 6.3%, achieved for A-IV sample in the visible UV spectrum. Sample A-IV showed prominent results in the temperature analysis with temperatures as low as 38.9°C in uncontrolled and 43.2°C in controlled source environments. The results from various analyses proved that MoS2 was an appropriate material for an antireflection coating to enhance the performance of polycrystalline solar cell.

Efficiency Improvement of Industrial Silicon Solar Cells by the POCl3 Diffusion Process

To improve the efficiency of polycrystalline silicon solar cells, process optimization is a key technology in the photovoltaic industry. Despite the efficiency of this technique to be reproducible, economic, and simple, it presents a major inconvenience to have a heavily doped region near the surface which induces a high minority carrier recombination. To limit this effect, an optimization of diffused phosphorous profiles is required. A "low-high-low" temperature step of the POCl3 diffusion process was developed to improve the efficiency of industrial-type polycrystalline silicon solar cells. The low surface concentration of phosphorus doping of 4.54 × 1020 atoms/cm3 and junction depth of 0.31 μm at a dopant concentration of N = 1017 atoms/cm3 were obtained. The open-circuit voltage and fill factor of solar cells increased up to 1 mV and 0.30%, compared with the online low-temperature diffusion process, respectively. The efficiency of solar cells and the power of PV cells were increased by 0.1% and 1 W, respectively. This POCl3 diffusion process effectively improved the overall efficiency of industrial-type polycrystalline silicon solar cells in this solar field.