Solidification Method Research Articles

Integrated approach for sustainable management of drilling residues using stabilisation and solidification techniques

Drilling operations, a critical phase in oil and gas extraction, generate substantial amounts of drilling fluids and cuttings containing hazardous materials, including heavy metals and hydrocarbons. If not managed properly, these by-products can cause severe environmental damage, such as soil contamination, water pollution, and disruption of ecosystems. As global efforts emphasize the importance of sustainability and environmental conservation, finding effective solutions for managing drilling waste becomes crucial.This study focuses on the treatment and recycling of drilling mud generated from the Zarzaitine oil fields, located in the Illizi basin, 30 kilometers east of In Amenas. The adopted methodology relies on stabilization and solidification (S/S) techniques, which are widely used to reduce the volume and toxicity of hazardous waste. These processes convert harmful drilling sludge into more stable and less toxic materials, minimizing the risks associated with its disposal.Implementing such solutions aligns with sustainable waste management principles in the oil and gas industry. By recycling drilling fluids and reducing hazardous waste, companies can meet stricter environmental regulations while lowering the environmental impact of their operations. Furthermore, the recycled products can sometimes be repurposed, promoting a circular economy approach.The findings of this research highlight the effectiveness of stabilization and solidification methods in mitigating environmental hazards. It demonstrates that proper waste treatment not only protects natural resources but also encourages a shift towards more environmentally responsible practices in oil and gas extraction. Through this approach, the Zarzaitine oil fields can serve as a model for sustainable waste management in the region.

Growth kinetics and microstructure transition of undercooled Fe7(CoNi)75B18 eutectic muti-principal element alloy

The mechanism of rapid solidification behavior of eutectic muti-principal element alloys (EMPEAs) is an eye-catching field. In this study, the novel Fe7(CoNi)75B18 EMPEA was undercooled via rapid solidification and B2O3 glass purification method and the maximum undercooling up to 190 K was achieved. A clear microstructure evolution path was identified with the undercooling: fully regular eutectic → primary dendrite and regular eutectic → primary dendrite and divorced eutectic. The orientation relationship (OR) between the primary (Fe, Co, Ni) phase and secondary B-rich phase was revealed both at low and medium undercoolings by electron backscatter diffraction (EBSD) analysis. The results show that the OR disappears at high undercooling (190 K) owing to the microstructure fragment and rotation during the post-recalescence. Furthermore, the growth velocity exponentially raised with the increase of undercooling. The maximum growth velocity of the primary phase was 1.152×10−1 m/s, which is significantly lower than binary alloys due to the sluggish kinetics effect of EMPEAs. This study helps to understand the solidification kinetics and microstructure transition of the novel EMPEA and has important implications for controlling the solidification process of more complex alloys.

The localized radial basis function collocation method for dendritic solidification, solid phase sintering and wetting phenomenon based on phase field

Phase-field has been effectively applied to many complex problems according to the mesh based method. However, the computational speed of the numerical method based on phase-field still needs improved. In this paper, an improved localized radial basis function collocation method (LRBFCM) based on the adaptive support domain is employed to the phase-field methods. The proposed adaptive support domain can increase the stability of the LRBFCM, and the improved LRBFCM is much more efficient than the traditional finite element method (FEM) in coupling with phase-field methods. The proposed approach is further applied to the single-phase dendrite solidification, two-phase sintering, and three-phase wetting phenomena. We compare the efficiency of the proposed LRBFCM with different numerical methods, which show that the LRBFCM combined with the Fourier spectral method can deal with the three-phase model with more than ten million nodes easily.

Direct Ink Writing 3D Printing Elastomeric Polyurethane Aided by Cellulose Nanofibrils.

3D printing of a flexible polyurethane elastomer is highly demandable for its potential to revolutionize industries ranging from footwear to soft robotics thanks to its exceptional design flexibility and elasticity performance. Nevertheless, conventional methods like fused deposition modeling (FDM) and vat photopolymerization (VPP) polyurethane 3D printing typically limit material options to thermoplastic or photocurable polyurethanes. In this research, a water-borne polyurethane ink was synthesized for direct ink writing (DIW) 3D printing through the incorporation of cellulose nanofibrils (CNFs), enabling direct printing of complex, monolithic elastomeric structures at room temperature that can maintain the designed structure. Additionally, a solvent-induced fast solidification (SIFS) method was introduced to facilitate room-temperature curing and enhance mechanical properties. The 3D-printed WPU structures demonstrated strong interfacial adhesion, exhibiting high ultimate tensile strength of up to 22 MPa and an elongation at break of 951%. The 3D-printed WPU structures also demonstrated outstanding resilience and durability, capable of enduring more than 100 cycles of compression and tension as well as withstanding vehicle crushing and heavy lifting. This method also shows suitability for 3D printing complex structures such as a vase and an octopus.

Study on Pore Water Pressure Model of EICP-Solidified Sand under Cyclic Loading

Under traffic load, earthquake load, and wave load, saturated sand foundation is prone to liquefaction, and foundation reinforcement is the key measure to improve its stability and liquefaction resistance. Traditional foundation treatment methods have many problems, such as high cost, long construction period, and environmental pollution. As a new solidification method, enzyme-induced calcium carbonate precipitation (EICP) technology has the advantages of economy, environmental protection, and durability. Through a triaxial consolidated undrained shear test under cyclic loading, the impacts of confining pressure (σ3), cementation number (Pc), cyclic stress ratio (CSR), initial dry density (ρd), and vibration frequency (f) on the development law of pore water pressure of EICP-solidified sand are analyzed and then a pore water pressure model suitable for EICP-solidified sand is established. The result shows that as σ3 and CSR increase, the rise rate of pore water pressure of solidified sand gradually accelerates, and with a lower vibration number required for liquefaction, the anti-liquefaction ability of solidified sand gradually weakens. However, as Pc, ρd, and f rise, the increase rate of pore water pressure of solidified sand gradually lowers, the vibration number required for liquefaction increases correspondingly, and its liquefaction resistance gradually increases. The test results are highly consistent with the predictive results, which show that the three-parameter unified pore water pressure model is suitable for describing the development law of A-type and B-type pore water pressure of EICP-solidified sand at the same time. The study results provide essential reference value and scientific significance in guidance for preventing sand foundations from liquefying.

A Feature of the Horizontal Directional Solidification (HDS) Method Affects the Microstructure of Al2O3/YAG Eutectic Ceramics

The solidification processes of two compositions, hypereutectic (21.0 mol% Y2O3–79.0 mol% Al2O3) and eutectic (18.5 mol% Y2O3–81.5 mol% Al2O3), were used via the horizontal directional solidification (HDS) method to produce two ingots with dimensions of 317 × 220 × 35 mm and 210 × 180 × 35 mm, respectively. The first ingot was heterogeneous and characterized by a two-layer structure with an expressed horizontal boundary, which is parallel to the solidification direction (an experimental fact observed for the first time), separating eutectic-type ceramics in the upper layer from the lower one containing the YAG dendrites. Considering the heat transfer feature characteristic of the HDS method and its action during the solidification of materials scattering thermal radiation, an explanation of the occurrence of such structure has been proposed. On this basis, the solidification parameters of the second ingot, providing its homogeneous structure, were selected. Characterization of the crystallographic texture and microstructure of both ingots revealed the advantage of the second solidification processing conditions.

Lithium Chloride-Mediated enhancement of dye removal capacity in Borneo bamboo derived nanocellulose-based nanocomposite membranes (NCMs)

Demand for sustainable materials for membrane fabrication is rapidly increasing, particularly in Sarawak coastal areas. nanocellulose emerges as a promising alternative for membrane development due to its availability, intrinsic biodegradability, and high strength. However, the hydrophobicity of nanocellulose limits its applicability in water treatment operations. Hence necessitating the need for innovative solutions. Herein, we examine the potential of bamboo-derived nanocellulose to enhance nanocomposite membrane-based water treatment systems by incorporating lithium chloride as a pore-forming additive. Nanocomposite membranes (NCMs) were synthesised using a LiCl-doped solution of nanocellulose and polyvinylidene fluoride (PVDF) through phase inversion and controlled solidification methods. The results show that nanocellulose incorporation induces structural alterations in NCMs, with reduced size in cellulose microfibrils. The crystallinity of nanocellulose was enhanced through interactions between PVDF and nanocellulose. The integration of nanocellulose along with lithium chloride was observed to have a significant impact on water permeation flux, attaining 104 L/m2h due to improved hydrophobicity and reduced fouling. In addition, the developed NCMs recorded 93 % methylene blue (MB) removal within 10 min. Revealing high potential of NCMs as an alternative and sustainable material for the development of nanocomposite membranes to mitigate contemporary challenges of water scarcity.

Development of large-volume 130TeO2 bolometers for the CROSS 2β decay search experiment

We report on the development of thermal detectors based on large-size tellurium dioxide crystals (45 × 45 × 45 mm), containing tellurium enriched in 130Te to about 91%, for the CROSS double-beta decay experiment. A powder used for the crystals growth was additionally purified by the directional solidification method, resulting in the reduction of the concentration of impurities by a factor 10, to a few ppm of the total concentration of residual elements (the main impurity is Fe). The purest part of the ingot (the first ∼ 200 mm, about 80% of the total length of the cylindrical part of the ingot) was determined by scanning segregation profiles of impurities and used for the 130TeO2 powder production with no evidence of re-contamination. The crystal growth was verified with precursors produced from a powder with natural Te isotopic composition, and two small-size (20 × 20 × 10 mm) samples were tested at a sea-level laboratory showing high bolometric and spectrometric performance together with acceptable 210Po content (below 10 mBq/kg). This growth method was then applied for the production of six large cubic 130TeO2 crystals and 4 of them were taken randomly to be characterized at the Canfranc underground laboratory, in the CROSS-dedicated low-background cryogenic facility. Two 130TeO2 samples were coated with a thin, 𝒪(100 nm), metal film in form of Al layer (on 4 sides) or AlPd grid (on a single side) to investigate the possibility to tag surface events by pulse-shape discrimination. Similarly to the small natural precursors, large-volume 130TeO2 bolometers show high performance and even better internal purity (210Po activity ∼ 1 mBq/kg, while activities of 228Th and 226Ra are below 0.01 mBq/kg), satisfying requirements for the CROSS and, potentially, next-generation experiments.

Luminescence and scintillation properties of TlCdCl3:Sb crystals

An ideal scintillator for X- and gamma-ray detection should have a high light yield and a high effective atomic number (Zeff). In this study, we developed undoped TlCdCl3 crystals and TlCdCl3:Sb (Sb: 0.5, 1.0 and 1.5 mol%) crystals with high Zeff (TlCdCl3:68.7), as candidate scintillators. The crystals were grown using the self-seeding solidification method, and their photoluminescence (PL) and scintillation properties were investigated. For the undoped TlCdCl3 crystals, emission peaks were observed at 460 nm and 485 nm in the PL and X-ray-induced radioluminescence (XRL) spectra, respectively. For the TlCdCl3:Sb crystals, the PL spectra showed emission peaks at 480, 480 and 500 nm, while the XRL spectra exhibited peaks at approximately 510 nm. The emission bands of the TlCdCl3:Sb crystals were shifted to longer wavelengths than those of the undoped TlCdCl3 crystals. The scintillation decay time constants for the undoped TlCdCl3 crystals were 51 and 2613 ns, whereas for the TlCdCl3:Sb crystals, they were in the range of 65–81 and 4550–7350 ns. These results suggest that the incorporation of Sb3+ ions induces long components of several thousand nanoseconds. The redshift and appearance of these long components indicate that Sb3+ ions act as new luminescence centers in the undoped TlCdCl3 crystal. The scintillation light yield of the TlCdCl3:Sb 1.0 mol% crystal was measured at 10,300 photons/MeV. The doping of Sb3+ ions into the TlCdCl3 lattice improved the scintillation light yield by up to four times compared to the undoped TlCdCl3 crystal.

Suitable material design of temperature-stabilizing device using phase change materials for electric power supply of nanosatellites

This study proposes a new passive thermal-control device utilizing phase-change materials (PCMs) that require minimal active thermal support, such as heaters, to achieve a high-performance and high-reliability power supply for nanosatellites and other space applications. This study evaluated two different PCMs as candidate materials for the device and compares their performances as thermal control devices. One was a solid–solid PCM based on vanadium dioxide doped with tungsten (VWO2), and the other was a microencapsulated PCM containing n-paraffin (NPH-MPCM). For integration into nanosatellites, it is essential to form a PCM as solid blocks. This report adopted a solidification method using epoxy resin (EP) as the binder and determined the optimal block composition for each PCM. The thermal-insulation properties of both PCM blocks in vacuum and low-temperature environments were evaluated and found to be almost equivalent. Considering that the latent heat of VWO2 is only approximately one-fifth that of NPH-MPCM, the practical application of VWO2 as a PCM was demonstrated. Furthermore, VWO2 exhibits a phase-change temperature hysteresis of 4 °C, which is significantly smaller than the 23 °C of NPH-MPCM. This characteristic is expected to help maintain a more constant temperature for power supplies in earth-orbiting micro/nanosatellites. Moreover, lithium-ion battery cells were incorporated into both VWO2-based and NPH-MPCM-based PCM blocks, and their charge–discharge behaviors were evaluated. Only the VWO2-based PCM block could maintain appropriate temperatures to ensure stable charge–discharge operation. Vacuum resistance results suggested that the VWO2-based PCM block is well-suited as a temperature-stabilizing device for electric power supplies in nanosatellites.

Research on Solidification Methods and Stabilization Mechanisms of Sulfate Saline Soils

In cold regions, saline soils can cause dissolution, settlement, and salt expansion of the roadbed under the influence of freeze–thaw cycles, so they need to be stabilized during road construction. In this study, lime, fly ash (FA), and polyacrylamide (PAM) were used to stabilize sulfate saline soils, and the stabilized saline soils were subjected to the unconfined compressive strength test (UCS), splitting test, and freeze–thaw cycle tests (FTs). The stabilization mechanism of the three materials on saline soils was also studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS). The test results showed that the addition of lime, FA, and PAM to saline soils can improve the mechanical properties and frost resistance of saline soils. After 28 d of curing, the UCS of FA-, PAM-, and lime-stabilized saline soils increased by at least 55%, 23%, and 1068%, respectively, and the splitting strength increased by at least 161%, 75%, and 2720%, respectively. After five freeze–thaw cycles, the residual strength ratios (BDRs) of the UCS of L2 (lime 8%), F2 (FA 11%), and P2 (PAM 1%) stabilized soils and saline soils were 71.78%, 56.42%, 39.05%, and 17.95%, respectively, and the decreasing trend tended to be stable. The saline soils stabilized by lime and FA were chemically stabilized, and their mechanical properties and frost resistance were better than the physical stabilization of PAM.

Enhanced control and efficiency in millimeter-scale composite droplets preparation

A microfluidic device utilising the flow focusing method was designed and fabricated for the high-throughput and controllable preparation of millimeter-scale water-in-oil (W1/O/W2) droplets. Two distinct flow focusing modes were employed in order to prepare the composite droplets. In the flow-focused axisymmetric jetting mode, the continuous phase propels the dispersed phase, forming a cone, which subsequently leads to a jet formation downstream of the small hole. When the outer phase is activated, perturbation growth interferes with downstream fragmentation, resulting in composite droplets with excellent monodispersity. In the dripping mode, the dispersed phase fails to form a jet downstream, and the interface disintegrates, resulting in droplet formation at the exit of the small orifice. In the jetting mode, the size and shell-to-core ratio of the generated droplets can be controlled by adjusting the volume of flow of the outer and inner phases, as well as the applied frequency. Furthermore, the applied perturbation allows for precise control of droplet size, which significantly reduces satellite droplet formation and enhances droplet monodispersity. In the dripping mode, the shell-to-core ratio is adjusted by manipulating the ratio of inner to outer flow rates, which is tailored to the specific requirements of the flow-focused dripping mode. The prepared compound droplets exhibit good monodispersity. Finally, the rotational solidification method can be employed to obtain spherical shells with a shell thickness of less than 20 μm. In conclusion, the flow focusing method is an effective, controllable, and stable method for synthesising millimetre-sized composite droplets.

Preparation of Magnetite-silica Composite by Non-firing Solidification Method and Its Microwave Heating Properties

Preparation of Magnetite-silica Composite by Non-firing Solidification Method and Its Microwave Heating Properties

A dynamic thermal radiation insulation method for directional solidification of polysilicon

To simplify the structure and reduce the high energy consumption of thermal insulation structures for polysilicon directional solidification equipment, an innovative cavity structure with a mirror and diffuse reflector was designed for thermal insulation. This method uses an internal thermal radiation cavity instead of a traditional insulation layer. Compared with the traditional insulation material, its volume was only 16.6 % of the crucible volume, and the energy consumption was reduced by 8.6 %. A mathematical model of the thermal radiation exchange in the cavity was established and solved analytically. Because of the design of mirror and reflector, the self-adjustment of the thermal radiation intensity and angle in the cavity was theoretically verified. It could automatically “trail” the temperature change on the sidewalls of the melt (crucible), and the dynamic thermal compensation was equivalent to an adiabatic construction. Three comparison experiments with a large ingot (0.9 m × 0.9 m × 0.35 m) were performed. When the cavity height to width ratio was greater than 3.33, the thermal compensation was poor and the quality of the ingot is lower than that of the others. The experiments showed that refractory brick and polished brass are a good combination for creating a cavity.

Properties of saline soil stabilized with fly ash and modified aeolian sand

Against the backdrop of saline soil solidification and the resource utilization of solid waste and aeolian sand in cold and arid regions, this study employs locally accessible fly ash and aeolian sand to solidify saline soil. By combining unconfined compressive strength tests, X-ray diffraction analysis, scanning electron microscopy, orthogonal experiments, and single-factor analysis, the strength characteristics, mineral composition, and interfacial structure changes of saline soil solidified with different freeze-thaw cycles and varying amounts of fly ash, aeolian sand, and alkali activators were investigated. The effects of each factor were analyzed to determine the optimal mixture ratio and to explore the solidification mechanism.The results indicate that the unconfined compressive strength of saline soil is most significantly enhanced when solidified with a combination of fly ash, aeolian sand, and alkali activators. The optimal mixture ratio was found to be 24 % fly ash, 7 % aeolian sand, and 4.5 mol/L alkali activator. With the incorporation of these solidifying materials, the failure mode of saline soil transitions from plastic to brittle, and the stress-strain curve exhibited a strain-softening behavior. The combined solidification method demonstrated the most pronounced effect in mitigating freeze-thaw damage, with the unconfined compressive strength of the solidified soil reaching 7.01 MPa after seven freeze-thaw cycles, compared to 0.03 MPa for the untreated soil, an increase by a factor of 234.This significant enhancement is attributed to the formation of substantial gel substances, which mitigate the strength loss caused by freeze-thaw cycles. The gel locking mechanism between particles in the solidified soil far exceeds the detrimental effects of freeze-thaw cycles, effectively inhibiting freeze-thaw deterioration. Additionally, the reaction pathways involving AFt and AFm phases reduce the content of SO42- and Cl- in the solidified soil, effectively suppressing salt expansion and significantly improving the soil's strength.

Impact of low-temperature and low-pressure mild oxidation after plasma solidification on electrical properties and reliability in ultra-thin SiON MOSFETs

The impact of different SiON manufacturing processes on performance and reliability behaviors has been investigated for the MOSFETs. The performance of devices composed of an ultrathin SiON film fabricated by the novel low-temperature and low-pressure mild oxidation after the plasma solidification (LLMOPS) method can be enhanced compared to conventional processes, which is attributed to the increased mobility. It is observed from secondary ion mass spectrometry analysis that the distribution of nitrogen with the LLMOPS process moves toward the upper surface of SiON. As a result, the p-MOSFET manufactured by the LLMOPS process exhibits lower electrical performance degradation during the NBTI stress, indicating that a reduction in nitrogen concentration at the Si/SiO2 interface contributes to improving NBTI behavior. It is also demonstrated that the inhibition of NBTI phenomena enhances the frequency stability on the ring oscillator with circuit simulation. Thus, the LLMOPS process is a promising approach to improve the performance and reliability of MOSFETs in mass production.

Preparation of Fibrous Three-Dimensional Porous Materials and Their Research Progress in the Field of Stealth Protection.

Intelligent and diversified development of modern detection technology greatly affects the battlefield survivability of military targets, especially infrared, acoustic wave, and radar detection expose targets by capturing their unavoidable infrared radiation, acoustic wave, and electromagnetic wave information, greatly affecting their battlefield survival and penetration capabilities. Therefore, there is an urgent need to develop stealth-protective materials that can suppress infrared radiation, reduce acoustic characteristics, and weaken electromagnetic signals. Fibrous three-dimensional porous materials, with their high porosity, excellent structural adjustability, and superior mechanical properties, possess strong potential for development in the field of stealth protection. This article introduced and reviewed the characteristics and development process of fibrous three-dimensional porous materials at both the micrometer and nanometer scales. Then, the process and characteristics of preparing fibrous three-dimensional porous materials through vacuum forming, gel solidification, freeze-casting, and impregnation stacking methods were analyzed and discussed. Meanwhile, their current application status in infrared, acoustic wave, and radar stealth fields was summarized and their existing problems and development trends in these areas from the perspectives of preparation processes and applicability were analyzed. Finally, several prospects for the current challenges faced by fibrous three-dimensional porous materials were proposed as follows: functionally modifying fibers to enhance their applicability through self-cross-linking; establishing theoretical models for the transmission of thermal energy, acoustic waves, and electromagnetic waves within fibrous porous materials; constructing fibrous porous materials resistant to impact, shear, and fracture to meet the needs of practical applications; developing multifunctional stealth fibrous porous materials to confer full-spectrum broadband stealth capability; and exploring the relationship between material size and mechanical properties as a basis for preparing large-scale samples that meet the application's requirement. This review is very timely and aims to focus researchers' attention on the importance and research progress of fibrous porous materials in the field of stealth protection, so as to solve the problems and challenges of fibrous porous materials in the field of stealth protection and to promote the further innovation of fibrous porous materials in terms of structure and function.

Enhancing the removal of Fe and Ti from metallurgical silicon by slagging-directional solidification

Metallurgical preparation of solar-grade silicon is the most popular method, benefiting from the low costs and environmentally friendly. The paper employed a metallurgical method to purify silicon and investigated the removal of Fe and Ti from silicon by directional solidification synergized with slagging refining (slagging-directional solidification, SDS). The result showed that lower solidification velocity and stronger cooling conditions during directional solidification (DS) contributed to removing Fe and Ti impurities from ingots. The concentrations of Fe and Ti at the beginning of the ingot obtained by DS at optimum conditions were 0.04 wt% and 0.002 wt%. Based on this, the influence of SDS on Fe and Ti was investigated, finding the concentrations of Fe and Ti at the beginning of the ingot were 0.021 wt% and 0.001 wt% with removal rates of 98.55 % and 98.86 %. Compared to ingots obtained by DS, the removal rates of Fe and Ti increased by 1.31 % and 1.13 %, respectively. The results showed that SDS has been proven to enhance the removal of Fe and Ti from ingot. Finally, the removal mechanism of SDS was analyzed. The method of directional solidification synergized with slagging refining was a novel method to purify with a low cost and environmentally friendly.

Purifying High-Purity Copper via Semi-Continuous Directional Solidification: Insights from Numerical Simulations

High-purity copper is essential for fabricating advanced microelectronic devices, particularly integrated circuit interconnects. As the industry increasingly emphasizes scalable and efficient purification methods, this study investigates the multi-physics interactions during the semi-continuous directional solidification process, utilizing a Cu-1 wt.%Ag model alloy. Coupled simulation calculations examine the spatial distribution patterns of the impurity element silver (Ag) within semi-continuously solidified ingots under varying pulling rates and melt temperatures. The objective is to provide technical insights into the utilization of the semi-continuous directional solidification method for high-purity copper purification. The findings reveal that increasing the pulling rate and melt temperature leads to a downward shift in the solid–liquid interface relative to the mold top during processing. Alongside the primary clockwise vortex flow, a secondary weak vortex emerges near the solid–liquid interface, facilitating the migration of the impurity element Ag toward the central axis and amplifying radial impurity fluctuations. Furthermore, diverse pulling rates and melt temperature conditions unveil a consistent trend along the ingot’s height, which is characterized by an initial increase in average Ag content, followed by stabilization and then a rapid ascent during the late stage of solidification, with higher pulling rates and melt temperatures expediting this rapid ascent. Leveraging these insights, a validation experiment using 4N-grade recycled copper in a small-scale setup demonstrates the effectiveness of the semi-continuous directional solidification process for high-purity copper production, with copper samples extracted at 1/4 and 3/4 ingot heights achieving a 5N purity level of 99.9994 wt.% and 99.9993 wt.%, respectively.

Crystallization processes for photovoltaic silicon ingots: Status and perspectives

The choice of the crystallization process plays a crucial role in determining the quality and performance of the photovoltaic (PV) silicon ingots, which are subsequently used to manufacture solar cells. Silicon ingots are typically grown using either the Czochralski (Cz) process or the direction solidification (DS) method, with each technique influencing the microstructure and defects density as well as the final solar cells’ performance. In this work, we describe these two processes with a brief overview of the main challenges. For monocrystalline silicon ingots, we discuss the role of crucible and bubble development as well as structure loss. For multicrystalline silicon ingots, we briefly review some of the methods that have been developed in the past years and present results of high-performance multicrystalline (HPMC) ingots.