Solution Growth Of Crystals Research Articles

Two-step nucleation and growth of crystals in a metastable solution with mass exchange with the environment

Two-step nucleation and growth of crystals in a metastable solution with mass exchange with the environment

In Situ Morphology Control for Solution‐Printable Organic Photovoltaics

AbstractThe morphology of the photoactive layer plays an important role in both the photoelectric effect and device performance of solution‐processed organic solar cells (OSCs). Optimizing the morphology requires precise control over the complex film formation kinetics, which are influenced by a range of factors from the solution state to the solid‐film state. This review delves into the in situ characterization technologies employed to understand the active layer formation process and explores strategies for controlling film formation during key stages, including solution aggregation, nucleation, crystal growth, and phase separation. Special attention is given to the mechanism by which these strategies enable real‐time morphology control during the printing process and their potential to facilitate direct printing of active layers with optimized morphology. The goal is to offer valuable insights and guidance for managing film formation kinetics in solution‐processed OSCs, ultimately addressing the challenges of real‐time morphology control in scale‐up printing and paving the way for high‐throughput production of post‐processing‐free devices.

A Revisit of Crystallization in Tin Halide Perovskite Thin Films: From Nucleation, Intermediate to Crystal Growth

AbstractPerovskite solar cells (PSCs) are exuding unique charm in the third generation of thin film solar cell technology with high power conversion efficiency (PCE) and low production cost. Recently, the lead‐free tin halide perovskite solar cells (TPSCs) have drawn significant research interests due to the advantages of low toxicity, near‐ideal bandgap and high carrier mobility. However, the rapid crystallization and easy oxidation limits the film quality and final performance of the solar cells. Therefore, the deposition of high‐quality tin halide perovskite films is key to the advance of TPSCs. In this review, the classical theory of solution nucleation and crystal growth is reviewed and correlated to the practical deposition of tin perovskite film. The physicochemical properties of tin perovskite with those of lead counterpart and the differences in the crystallization process is carefully compared. On this basis, recent regulation strategies are systematically summarized in terms of the nucleation management, intermediate phase engineering and crystal growth regulation. In addition, the preparation of mixed tin‐lead (Sn‐Pb) PSCs toward high performance is also discussed, as well as the limiting factors for device performance and stability. Finally, the future challenges and prospects of the crystallization regulation are discussed toward more efficient and stable TPSCs.

Концентрационные потоки. 230 лет в кристаллогенетической повестке

We briefly outlined the history of discovery and study of concentration flows accompanying the growth and dissolution of crystals in solutions. Various crystallogenic consequences associated with concentration flows (changes in the mechanisms of transport of matter to the growing crystal, differences in the growth of the upper and lower faces, distortion of crystal shape, occurrence of hydrodynamic boundary layer around a crystal together with the diffusion layer, etc.) were described. The phenomenon of concentration differentiation (stratification) of the solution under the influence of concentration flows was especially analyzed. The criteria conditions for differentiation of the solution during crystal growth were determined.

Unveiling the effect of hypophosphorous acid for the growth of high quality Cs3Cu2I5 single crystals

The zero-dimensional copper halide perovskite Cs3Cu2I5 displays extraordinary luminescence and scintillation characteristics, and high-quality crystals are extremely desirable for exploring the commercial applications. Currently, the most critical issue in the solution growth of Cs3Cu2I5 crystals is the easy oxidation of halides, which significantly hinders the optimization of crystal qualities. The hypophosphorous acid (H3PO2) has been applied to inhibit the oxidation, nevertheless, the related mechanism is elusive and has been largely ignored. Herein, Cs3Cu2I5 crystals have been grown from N, N-Dimethylformamide (DMF) solvent by the antisolvent vapor-assisted crystallization (AVC) method. It is verified that H3PO2 effectively prevents the oxidation of Cs3Cu2I5 by rapidly reducing Cu2+ and I3−, maintaining the stability of the precursor solution and continuously suppressing oxidation during the whole growth process. Meanwhile, by increasing the acidity of the solution, H3PO2 dissolve precursor colloids and efficiently enhance the solubility of halides. Thus, the addition of H3PO2 favors the rapid growth of centimeter-sized Cs3Cu2I5 crystals with well-defined crystallographic planes within several days. As excellent gamma ray scintillator, the crystal exhibits high light yield of 38000 photons/MeV, with energy resolution of 5.6 % under 662 keV radiation from a 137Cs source. This work deeply elucidates new insight into the critical effect of H3PO2 in the DMF based solution crystal growth, facilitating the preparation of large-size and high-performance copper halide perovskite crystals.

In Situ Monitoring and Tuning Multilayer Stacking of Polymer Lamellar Crystals in Solution with Aggregation-Induced Emission.

Many types of self-assembled 2D materials with fascinating morphologies and novel properties have been prepared and used in solution. However, it is still a challenge to monitor their in situ growth in solution and to control the number of layers in these materials. Here, we demonstrate that the aggregation-induced emission (AIE) effect can be applied for the in situ decoupled tracing of the lateral growth and multilayer stacking of polymer lamellar crystals in solution. Multilayer stacking considerably enhances the photoluminescence intensity of the AIE molecules sandwiched between two layers of lamellar crystals, which is 2.4 times that on the surface of monolayer crystals. Both variation of the self-seeding temperature of crystal seeds and addition of a trace amount of long polymer chains during growth can control multilayer lamellar stacking, which are applied to produce tunable fluorescent patterns for functional applications.

Enhancing growth speed of 3C–SiC using solution growth method by a new low temperature Mn-based cosolvent

Solution growth is a promising method for rapidly and stably preparing high-quality silicon carbide (SiC) single crystals. However, the coexistence of polycrystalline parasitism and solid inclusions during the growth of SiC in high-temperature solutions above 1800 °C still poses a serious threat to the quality of single crystals. Herein, we introduce an innovative Mn-based cosolvent for controlling the stable and fast growth of cubic-type silicon carbide (3C–SiC) single crystals at low temperatures. Firstly, our thermodynamic analysis reveals that SiC is the only stable solid compound in the low-temperature solution (1500–1600 °C) of the Si–Mn–C system, which is an important condition for the stable growth of crystals. Compared to typical solvents like Si–Cr, Si–Ti, and Si–Fe, the Si–Mn solvent exhibits the highest solubility and supersaturation for carbon. Secondly, our solubility calculations of SiC in the solvent show that the Mn-rich solvent can significantly increase the solubility of SiC. Thirdly, we successfully grew 3C–SiC single crystals from Si–Mn solution at 1500 °C without other SiC polymorphs produced. Rapid growth of SiC crystals in Mn-rich solution was achieved by modulating the content of Mn. Our work highlights the superiority of Si–Mn cosolvents in facilitating rapid growth of 3C–SiC single crystals at low temperatures. It introduces a novel approach by applying phase diagram calculation techniques to design suitable solvent systems for the solution growth of SiC single crystals.

Perovskite Single Crystals with Self‐Cleaning Surface for Efficient Photovoltaics

AbstractMetal halide perovskite single crystals are promising for diverse optoelectronic applications. As a universal issue of solution‐grown perovskite single crystals, surface contamination causes adverse effect on material properties and device performance. Herein, learning from the self‐cleaning effect of lotus leaf, we address the surface contamination issue by introducing an amphiphilic long‐chain organic amine into the perovskite crystal growth solution. Self‐assembly of CTAC provides a hydrophobic crystal surface, inducing spontaneous removal of residual growth solution, which results in clean surface and better optoelectronic properties of perovskite single crystals. An impressive efficiency of 23.4 % is obtained, setting a new record for FAxMA1‐xPbI3 single‐crystal perovskite solar cells (PSCs). Moreover, our strategy also applies to perovskite single crystals with different morphology and composition, which may contribute to improvement of other single‐crystal perovskite optoelectronic devices.

Perovskite Single Crystals with Self-Cleaning Surface for Efficient Photovoltaics.

Metal halide perovskite single crystals are promising for diverse optoelectronic applications. As a universal issue of solution-grown perovskite single crystals, surface contamination causes adverse effect on material properties and device performance. Herein, learning from the self-cleaning effect of lotus leaf, we address the surface contamination issue by introducing an amphiphilic long-chain organic amine into the perovskite crystal growth solution. Self-assembly of CTAC provides a hydrophobic crystal surface, inducing spontaneous removal of residual growth solution, which results in clean surface and better optoelectronic properties of perovskite single crystals. An impressive efficiency of 23.4 % is obtained, setting a new record for FAx MA1-x PbI3 single-crystal perovskite solar cells (PSCs). Moreover, our strategy also applies to perovskite single crystals with different morphology and composition, which may contribute to improvement of other single-crystal perovskite optoelectronic devices.

Growth of large norsethite crystals in aqueous ammonium nitrate solutions

Crystallization of norsethite [BaMg(CO3)2] receives considerable attention as a key for solving geological problems, and environmental and resource issues. Noresthite is poorly soluble in water, and is synthesized via witherite [BaCO3] by solution-mediated transformation. In contrast, owing to the difficulties such as tremendous growth time and consideration of multi-step reactions, the shape and size of norsethite were not satisfactory for further investigations so far. Here we tried to increase the solubility of the crystals to overcome these difficulties of the growth by adding NH4NO3. The solubilities of norsethite and witherite in the presence of NH4NO3 were ∼35 and ∼45 times higher than those in the absence of NH4NO3, respectively. At 90 °C, the growth rate of norsethite in NH4NO3 solutions was ∼17 times higher than that in NH4NO3-free solutions, and norsethite in NH4NO3 solutions nucleated immediately after mixing the raw materials. Finally, we succeeded in synthesizing bulky norsethite crystals of 170 μm size only in one month, utilizing 0.1–1 M NH4NO3 solutions of 90 °C. We could explain the appearance of large norsethite, considering that norsethite dominantly consumes the solute by adding NH4NO3 compared with witherite. The findings provide a breakthrough in the growth technique of double carbonates.

Data-Driven Reactivity Predictions between a Solute and Solvent for Inorganic Crystal Growth in Solution

Data-Driven Reactivity Predictions between a Solute and Solvent for Inorganic Crystal Growth in Solution

A General Analytical Solution for Two-Dimensional Columnar Crystal Growth during Laser Beam Welding of Thin Steel Sheets

A technique for calculating the main solidification parameters for a two-dimensional columnar crystal growth during complete penetration laser beam welding of thin steel sheets was developed. Given that the weld pool interface is described by Lamé curves (superellipses) within the horizontal plane of growth, general analytical solutions were derived for the geometry of the crystal axis and the corresponding growth rate and cross-sectional area of the crystal. A dimensionless analysis was performed to provide insights on the dependence of the solidification parameters on the shape and dimensions of the rear part of the weld pool boundary. The derived solutions were applied for the case of complete penetration laser beam keyhole welding of 2 mm thick 316L austenitic chromium-nickel steel sheets. It was shown that the reconstruction of the weld pool boundary with Lamé curves provides higher accuracy and flexibility compared to results obtained with elliptical functions. The validity of the proposed technique and the derived analytical solutions was backed up by a comparison of the obtained solutions to known analytical solutions and experimentally determined shapes and sizes of the crystals on the top surface of the sheet. The dimensions of the calculated crystal axis correlated well with the experimentally obtained results.

Assessing an aqueous flow cell designed for in situ crystal growth under X-ray nanotomography and effects of radiolysis products.

Nucleation and growth of minerals has broad implications in the geological, environmental and materials sciences. Recent developments in fast X-ray nanotomography have enabled imaging of crystal growth in solutions in situ with a resolution of tens of nanometres, far surpassing optical microscopy. Here, a low-cost, custom-designed aqueous flow cell dedicated to the study of heterogeneous nucleation and growth of minerals in aqueous environments is shown. To gauge the effects of radiation damage from the imaging process on growth reactions, radiation-induced morphological changes of barite crystals (hundreds of nanometres to ∼1 µm) that were pre-deposited on the wall of the flow cell were investigated. Under flowing solution, minor to major crystal dissolution was observed when the tomography scan frequency was increased from every 30 min to every 5 min (with a 1 min scan duration). The production of reactive radicals from X-ray induced water radiolysis and decrease of pH close to the surface of barite are likely responsible for the observed dissolution. The flow cell shown here can possibly be adopted to study a wide range of other chemical reactions in solutions beyond crystal nucleation and growth where the combination of fast flow and fast scan can be used to mitigate the radiation effects.

Nonclassical crystal growth and growth rate hysteresis observed during the growth of curcumin in impure solutions

Partially dissolved crystals of curcumin grow faster and exhibit an accelerated growth rate hysteresis.

Steps behaving badly: Nonlinear dynamics and a terrace-loading instability during solution growth of lysozyme crystals

A detailed finite-element model for step motion during solution crystal growth is applied to analyze the nonlinear growth dynamics of lysozyme. Insights from this model are applied to develop a much simpler, lumped-parameter model to describe step motion for this growth system. Bifurcation analysis applied to the lumped-parameter model demonstrates a critical bulk supersaturation at which an equidistant step train loses stability, via a supercritical Hopf bifurcation, to a stable, time-periodic system that exhibits a single step bunch. As supersaturation is further increased, additional bifurcations lead to more complicated behaviors, such as quasi-periodic patterns, multiple step bunches, and period doubling. The initial instability of the step train arises from the dynamics of terrace loading due to slow adsorption and step incorporation kinetics under high bulk supersaturation. These effects cause a time lag in the surface supersaturation level with respect to changes in terrace width, producing a phase shift of the surface supersaturation field in the direction of step motion and driving the formation of step bunches.

A Combined Model for Kinetic Clumped Isotope Effects in the CaCO3‐DIC‐H2O System

AbstractMost Earth surface carbonates precipitate out of isotopic equilibrium with their host solution, complicating the use of stable isotopes in paleoenvironment reconstructions. Disequilibrium can arise from exchange reactions in the DIC‐H2O system as well as during crystal growth reactions in the DIC‐CaCO3 system. Existing models account for kinetic isotope effects (KIEs) in these systems separately but the models have yet to be combined in a general framework. Here, an open‐system box model is developed for describing disequilibrium carbon, oxygen, and clumped (Δ47, Δ48, and Δ49) isotope effects in the CaCO3‐DIC‐H2O system. The model is used to simulate calcite precipitation experiments in which the fluxes and isotopic compositions of CO2 and CaCO3 were constrained. Using a literature compilation of equilibrium and kinetic fractionation factors, modeled δ18O and Δ47 values of calcite are in good agreement with the experimental data covering a wide range in crystal growth rate and solution pH. This relatively straightforward example provides a foundation for adapting the model to other situations involving CO2 absorption (e.g., corals, foraminifera, and high‐pH travertines) or degassing (e.g., speleothems, low‐pH travertines, and cryogenic carbonates) and/or mixing with other dissolved inorganic carbon sources.

Live Visualization of the Nucleation and Growth of Needle-Like Hydroxyapatite Crystals in Solution by In Situ TEM

Live Visualization of the Nucleation and Growth of Needle-Like Hydroxyapatite Crystals in Solution by In Situ TEM

Large-Area Synthesis of Ultrathin, Flexible, and Transparent Conductive Metal-Organic Framework Thin Films via a Microfluidic-Based Solution Shearing Process.

Iminosemiquinone-linker-based conductive metal-organic frameworks (c-MOFs) have attracted much attention as next-generation electronic materials due to their high electrical conductivity combined with high porosity. However, the utility of such c-MOFs in high-performance devices has been limited to date by the lack of high-quality MOF thin-film processing. Herein, a technique known as the microfluidic-assisted solution shearing combined with post-synthetic rapid crystallization (MASS-PRC) process is introduced to generate a high-quality, flexible, and transparent thin-film of Ni3 (hexaiminotriphenylene)2 (Ni3 (HITP)2 ) uniformly over a large-area in a high-throughput manner with thickness controllability down to tens of nanometers. The MASS-PRC process utilizes: 1) a micromixer-embedded blade to simultaneously mix and continuously supply the metal-ligand solution toward the drying front during solution shearing to generate an amorphous thin-film, followed by: 2) immersion in amine solution for rapid directional crystal growth. The as-synthesized c-MOF film has transparency of up to 88.8% and conductivity as high as 37.1 S cm-1 . The high uniformity in conductivity is confirmed over a 3500 mm2 area with an arithmetic mean roughness (Ra ) of 4.78nm. The flexible thin-film demonstrates the highest level of transparency for Ni3 (HITP)2 and the highest hydrogen sulfide (H2 S) sensing performance (2,085% at 5ppm) among c-MOFs-based H2 S sensors, enabling wearable gas-sensing applications.

Uncovering growth species of multivariate MOFs in liquid phase by mass spectrometry

The unveiling of MOF growth mechanism is hampered by the lack of fundamental knowledge about the very early stage of nucleation, especially the form and ratio of molecular species in the solution for crystal growth. Herein, we report the detection of growth species for a series of MOFs with mono-linker, Cu-MOF-2-BDC and Cu-MOF-2-NDC, and two linkers, MTV-MOF-2-(C4H4)x, by high resolution ESI-MS, where a large variety of Cu-containing species are identified unambiguously. The solvent molecules such as H2O, methanol and DMF participate in the formation of these species, other than ethanol. Furthermore, in the growth solution of MTV-MOF-2-(C4H4)x, growth species containing two different organic linkers are observed. The feeding ratio is not the only factor controlling the distribution of growth species for MTV-MOFs, but also the solvent involves in coordination, an aspect usually overlooked previously.

Effect of additive concentration on water solution under vacuum ambient: A molecular dynamics simulation study

In order to explore the effect of different concentrations of additives on aqueous solution in vacuum ambient, this paper uses molecular dynamics simulation method to study different concentrations of magnesium chloride (MgCl2) aqueous solution, ethylene glycol aqueous solution and nano iron oxide (nano-Fe3O4) aqueous solution. The radial distribution function of atoms, the water molecules’ self-diffusion coefficient and the type and number of hydrogen bonds are analyzed in detail. The dynamic behavior between water molecules and chloride and alcohol molecules in the solution is revealed. The results show that the additives affect the crystallization of the solution by inhibiting the self-diffusion rate of water molecules, and the iron oxide nanoclusters exhibit the most obvious behavior. Meanwhile, the added additives can also restrain the formation of hydrogen bonds between water molecules in solution. This suppresses the hydrogen bonds between two water molecules. At the same time, it reduces the diffusivity of water molecules. These effects weaken the tendency of water molecules to migrate to the nucleus, and can curb the nucleation and growth of ice crystals in the aqueous solution to a certain extent. This research will provide reference value in the selection of ice-making working fluid. Nano-iron oxide has better performance than MgCl2, and glycol solution is not conducive to vacuum ice making.