Journal of Crystal Growth最新文献

{"title":"Machine learning framework for derivation and optimization of Cz-YAG crystal growth recipe","authors":"Kunal Meshram ,&nbsp;Milena Petkovic ,&nbsp;Martin Holena ,&nbsp;Natasha Dropka","doi":"10.1016/j.jcrysgro.2025.128451","DOIUrl":"10.1016/j.jcrysgro.2025.128451","url":null,"abstract":"<div><div>We present a generalizable machine learning framework for rapid, dynamic optimization of Czochralski-grown undoped yttrium aluminum garnet (YAG) crystal growth recipes. This framework addresses the high cost and slow iteration cycles of conventional experimental and computational approaches. Steady-state computational fluid dynamics (CFD) simulations at only three distinct crystallization stages are combined with symbolic regression (SISSO++) and artificial neural network (ANN) surrogate models, enabling accurate, multi-objective optimization of process parameters at any crystallization stage around the CFD training window. Trained on 423 high-fidelity CFD cases, the surrogates predict key quality indicators (power, interface deflection, axial temperature gradient, and maximum von Mises stress) with high accuracy. Using an NSGA-II evolutionary optimization pipeline, we identify stage-wise Pareto-optimal settings that closely approximate fully dynamic growth while requiring only a fraction of the resources of direct CFD or experiment. The resulting dynamic process recipe prescribes stage-specific adjustments to rotation rate, pulling rate, and heater position, ensuring flat interfaces, target-aligned thermal gradients, and reduced mechanical stress across the crystallization window. Full CFD validation confirms the physical realizability and quality of the optimized recipes. This framework accelerates process development by orders of magnitude and provides an extensible platform for adaptive, data-driven oxide crystal manufacturing.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128451"},"PeriodicalIF":2.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient and performance pomegranate-derived anthocyanin dye-based DSSCs enabled by one-step hydrothermal growth of ZnO-SnO heteronanostructures","authors":"Mustafa Biçer","doi":"10.1016/j.jcrysgro.2025.128453","DOIUrl":"10.1016/j.jcrysgro.2025.128453","url":null,"abstract":"<div><div>A one-step hydrothermal synthesis approach was used to produce nanostructured ZnO, SnO, and ZnO-SnO heterojunction photoanodes on fluorine-doped tin oxide (FTO) substrates. Four distinct photoanode configurations ZnO (S₁), ZnO-SnO heteronanostructures (HNSs) (S₂ and S₃), and SnO (S₄) were designed to thoroughly investigate the effect of compositional and structural alterations on film form, crystallinity, and optoelectronic capabilities. The thin films were studied using scanning electron microscopy (SEM) for surface morphology, X-ray diffraction (XRD) for phase identification, Raman spectroscopy for vibrational analysis, UV–Vis spectroscopy for optical band gap estimation, and Fourier-transform infrared spectroscopy (FTIR) to identify the chemical bonding and metal–oxygen vibrations. The FTIR spectra revealed Zn–O stretching vibrations and Sn–O vibrations, confirming the formation of the ZnO-SnO HNSs. The photoanodes were sensitized using anthocyanin dye derived from pomegranate juice, a more sustainable alternative to synthetic dyes, and then converted into dye-sensitized solar cells (DSSCs) using the AN50 electrolyte. The S₂-based cell had the highest short-circuit current density (J_sc) and lowest charge transfer resistance (R_ct), resulting in a conversion efficiency (η) of 0.592 %. These findings highlight ZnO-SnO HNS’ exceptional performance and potential as environmentally friendly photoanode materials for next-generation DSSCs.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128453"},"PeriodicalIF":2.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Report from the meetings of the International Organization for Crystal Growth governing bodies held during the ICCGE-21 Conference in Xi’an, China, August 03–08, 2025","authors":"Christiane Frank-Rotsch","doi":"10.1016/j.jcrysgro.2025.128445","DOIUrl":"10.1016/j.jcrysgro.2025.128445","url":null,"abstract":"","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128445"},"PeriodicalIF":2.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Fe in structural and electrical properties in GaSb grown by TVDS technique","authors":"Gayatree Tripathy,&nbsp;Diana Pradhan,&nbsp;Sushanta Kumar Kamilla","doi":"10.1016/j.jcrysgro.2025.128423","DOIUrl":"10.1016/j.jcrysgro.2025.128423","url":null,"abstract":"<div><div>Gallium Antimonide (GaSb) proves to be a suitable substrate material in mid-infrared optoelectronic, spintronic and high speed electronic devices due to its lattice compatibility with the other compound semiconductors. Bandgap tuning, magnetic behaviour as well as tailoring the defects that directly impact the carrier mobility and conductivity can be done with doping transition metals. The present work involves growth of Fe doped GaSb by customized in-house horizontal “Thermo-Vertical Directional Solidification” (TVDS) apparatus. This compound semiconductor processing apparatus facilitates both the synthesis of the melt and the crystal growth process under precise thermal control of 1⁰C/min accuracy. Phase formation was confirmed by room temperature X-ray Diffraction (XRD) pattern which shows little lattice expansion with Fe doping at Ga site. Morphological study using Scanning Electron Microscopy (SEM) images reported average etch pit density of 2.1 × 10⁵ cm⁻² on the surface. The crystallite size from XRD and sub-grain size from SEM are nearly similar in dimension. Hall effect measurement results showed increase in mobility and carrier concentration while the resistivity value decreases. Similar changes in electrical parameters were further confirmed by the Dielectric Spectroscopy that give insights to different kinds of polarization mechanisms due to dopant-induced additional <em>p</em>-type carriers.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128423"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quasi-discrete modeling of step-flow dynamics: capturing bunching and debunching in sic solution growth","authors":"C.W. Lan","doi":"10.1016/j.jcrysgro.2025.128420","DOIUrl":"10.1016/j.jcrysgro.2025.128420","url":null,"abstract":"<div><div>Step-flow dynamics during SiC solution growth critically shape surface morphology and defect formation, yet conventional models often average step densities or encounter front-tracking singularities, missing transient bunching and debunching. We introduce a quasi-discrete 2D/3D model that couples advection–diffusion transport with Gaussian-regularized Robin boundary conditions, representing macrosteps as localized, integral-matched sinks. Each macrostep is resolved by a few Gaussian-weighted nodes while solute transport is computed on a fine finite-element mesh, ensuring stability and mass conservation. Simulations reveal that parallel flow drives strong bunching, producing wide terraces with amplified supersaturation; bunched steps advance more slowly due to solute depletion, while high-supersaturation pockets accelerate leading steps and trigger debunching. Conversely, anti-parallel flow advects depletion upstream and preserves uniform step spacing, with no bunching across tested conditions. In three dimensions, parallel flow yields stripe coalescence, while anti-parallel flow stabilizes step trains. By quantifying terrace supersaturation’s link to polytype nucleation, this robust, efficient model offers a predictive tool for optimizing step morphology and minimizing defects in high-quality SiC crystal growth.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128420"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145532754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle swarm optimization-optimized long short-term memory prediction and Model-Free Adaptive Control for Czochralski silicon crystal growth","authors":"Lin Hou ,&nbsp;Dedong Gao ,&nbsp;Shan Wang ,&nbsp;Wenyong Zhang ,&nbsp;Haixin Lin ,&nbsp;Yan An ,&nbsp;Xin Liu","doi":"10.1016/j.jcrysgro.2025.128421","DOIUrl":"10.1016/j.jcrysgro.2025.128421","url":null,"abstract":"<div><div>In the manufacturing of Czochralski-grown silicon single crystals, production control mainly relies on operator experience and conventional feedback strategies, which are often insufficient for addressing the nonlinear, time-varying nature and sensitivity to disturbances of the process. Consequently, real-time tracking of key parameter dynamics remains challenging, resulting in adjustment delays and limiting improvements in product quality and production efficiency. To overcome these challenges, this study proposes a hybrid framework that integrates a Particle Swarm Optimization (PSO)-based Long Short-Term Memory (LSTM) prediction model with a Model-Free Adaptive Control (MFAC) method. PSO is employed to optimize the hyperparameters of LSTM and MFAC, thereby improving prediction accuracy and enhancing the responsiveness and stability of diameter regulation. Experimental results demonstrate that the PSO-LSTM prediction model significantly improves prediction accuracy, enabling more effective decision support during crystal growth. Moreover, the combined PSO-MFAC strategy achieves faster diameter control response than traditional PID control. This work integrates predictive modeling and advanced control techniques into the Czochralski silicon crystal growth process, offering a practical approach to enhancing production reliability and efficiency.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128421"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of annealing process and seed layer control on the crystallization characteristics and optoelectronic properties of β-Ga2O3 films fabricated by ALD","authors":"Ziyu Yang ,&nbsp;Zihua Ma ,&nbsp;Jianghai He ,&nbsp;Chufeng Hou ,&nbsp;Qi Liu ,&nbsp;Shihao Xia ,&nbsp;Kongli Ran ,&nbsp;Qiang Wang ,&nbsp;Yuefei Zhang ,&nbsp;Fei Chen","doi":"10.1016/j.jcrysgro.2025.128427","DOIUrl":"10.1016/j.jcrysgro.2025.128427","url":null,"abstract":"<div><div>This study utilizes Atomic Layer Deposition (ALD) technology, employing Trimethylgallium (TMG) and Ozone (O₃) as precursors to fabricate Ga₂O₃ thin films. To enhance the crystallinity of the films, the effects of seed layers and annealing processes on the Ga₂O₃ thin films were investigated. High-quality β-Ga₂O₃ thin films were successfully grown on sapphire substrates. Experimental results indicate that directly depositing Ga₂O₃ on sapphire substrates did not yield satisfactory β-Ga₂O₃ films. To improve the crystallinity, a Ga₂O₃ seed layer was prepared on the sapphire substrate, and high-temperature annealing was employed to promote crystallization of the Ga₂O₃ seed layer, providing artificial nucleation sites for subsequent thin film deposition. The influence of the annealing temperature and seed layer thickness on the quality of the secondary Ga₂O₃ films was also studied. It was found that a seed layer with a thickness of 16.5 nm, followed by annealing at 1000 °C, resulted in Ga₂O₃ films with optimal crystallinity. After the deposition of the thin film, post-deposition annealing was performed to investigate the effects of annealing temperature on the structural and optical properties of the Ga₂O₃ films. The results show that with increasing annealing temperature, the optical band gap of the films enlarged, the proportion of high-valence gallium increased, and the crystallinity improved. Thus, it can be concluded that optimized annealing conditions lead to higher quality Ga₂O₃ films. The optical band gap of the Ga₂O₃ film treated with 30 min of annealing reached its maximum value of approximately 5.24 eV. Under a 5 V bias, the photocurrent was 1.9 × 10⁻⁴ A, the dark current was 4.9 × 10⁻⁷ A, and the photo-dark ratio was 388, which showed significant improvement compared to the as-deposited sample. At a 10 V bias, the device’s response time (τ_x) was 0.3 s, and its decay time (τd) was 0.28 s.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128427"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of directly grown multiwalled carbon nanotube as intermediate layers for GaN on c-plane sapphire","authors":"Gulnaz Gahramanova ,&nbsp;Rasim Jabbarov ,&nbsp;Oliver Rettig ,&nbsp;Imamaddin Amiraslanov ,&nbsp;Irada Mammadova ,&nbsp;Ferdinand Scholz","doi":"10.1016/j.jcrysgro.2025.128425","DOIUrl":"10.1016/j.jcrysgro.2025.128425","url":null,"abstract":"<div><div>This work investigates the role of directly synthesized multiwalled carbon nanotube (MWCNT) as an intermediate layer for the growth of gallium nitride (GaN) on c-plane sapphire. MWCNTs forests were grown on c-plane sapphire using aerosol-assisted chemical vapor deposition (A-CVD), and the structural and crystalline characteristics of these MWCNT templates were confirmed by Raman spectroscopy and powder X-ray diffraction (PXRD). Subsequently, GaN layers were grown via Metal-Organic Vapor Phase Epitaxy (MOVPE) on both bare c-sapphire and MWCNT/c-sapphire templates.</div><div>Structural and optical analyses (SEM, HRXRD, and low-temperature PL) reveal that GaN grown on MWCNTs is polycrystalline and exhibits reduced crystalline quality compared to GaN/sapphire, confirming a fundamentally different growth mode. Despite this, the hybrid GaN/MWCNT architecture exhibits significantly enhanced electrical conductivity. At 3 MHz, the AC conductivity of GaN/MWCNT/sapphire reaches ∼7 × 10³ µS, compared to ∼4.5 × 10² µS for GaN/sapphire. Under DC bias, the current at 20 V increases from ∼10⁻⁸ A (GaN/sapphire) to the milliamp range (10⁻³ A) for GaN/MWCNT/sapphire. These results demonstrate that MWCNT forests do not serve as a replacement for high-quality epitaxial GaN but instead enable a non-conventional GaN growth platform—porous, conductive, and weakly bonded to the substrate—opening pathways for GaN architectures relevant to sensing, catalytic interfaces, UV detection, and future transferable/lift-off GaN films.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128425"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A reitveld refinement in WPPF analysis for crystallographic behavior study of nanocrystal anatase TiO2 synthesized by ultrasonic-assisted sol–gel method and its photocatalytic activity","authors":"Mirza Nusrat Sweety ,&nbsp;Shariful Islam","doi":"10.1016/j.jcrysgro.2025.128424","DOIUrl":"10.1016/j.jcrysgro.2025.128424","url":null,"abstract":"<div><div>A novel crystallographic study has been conducted on a simplified synthesis of anatase TiO₂ nanocrystals derived from a sol–gel process, utilizing TTIP as the precursor at a pH of 2, assisted by ultrasonic means. The Reitveld refinement analysis performed using whole powder pattern fitting (WPPF) confirmed the complete formation of the TiO₂ anatase, verifying its tetragonal structure [α = β = γ = 90.0°; a = b = 3.7877 Å, c = 9.5090 Å]. Peak profiling indicated that the highest preferred orientation occurred along the (1<!--> <!-->0<!--> <!-->1) plane at 2θ = 25.357°, with a d-spacing of 0.35096 nm and an intensity of 6913 cps. The computed unit cell volume was 136.424 Å³, and additional measurements indicated a dislocation density of 0.00615 nm⁻², lattice strain of 0.58 %, microstrain of 0.00815, crystallinity of 63.279 %, and a crystallinity index of 1.37, all suggesting lattice expansion and a significant capacity for defect tolerance, crucial for applications in electronics and catalysis. According to the Scherrer equation, the average crystallite size was determined to be 12.75 nm; using the Monshi-Scherrer model, it was calculated at 12.17 nm; the Williamson-Hall model yielded 27.57 nm; the LSLM of the Scherrer equation resulted in 13.57 nm; the Size-Strain plot model estimated it to be 6.48 nm; and the Halder-Wagner model provided a size of 7.20 nm. Energy dispersive spectroscopy (EDS) analysis confirmed the elemental purity, showing 34.89 % Ti and 65.11 % O, while scanning electron microscopy (SEM) revealed a uniform distribution of non-clumped nanoparticles. The UV study show cased that a blue-shifted intense absorption peak of T_A (3.31 eV) compared to the bulk material reported in the literature (3.2 eV). The maximum photo-degradation efficiency under the dosage 30 mg, initial dye concentration 10 ppm, degradation time 60 min were found to be 98.8 %. By integrating a straightforward synthesis approach with comprehensive refinement, this detailed analysis of structural, optical and surface morphology along with photo-catalytic activity provides a reliable foundation for the production of pure anatase phase TiO₂ nanocrystals.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"675 ","pages":"Article 128424"},"PeriodicalIF":2.0,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145570925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally driven growth of MAPbBr3 single crystals","authors":"Tzu-Lung Chang ,&nbsp;Yu-Li Hsieh ,&nbsp;Hseuh-Hsing Hung ,&nbsp;Jau-Wern Chiou ,&nbsp;Hui-Huang Hsieh","doi":"10.1016/j.jcrysgro.2025.128410","DOIUrl":"10.1016/j.jcrysgro.2025.128410","url":null,"abstract":"<div><div>Methylammonium lead tribromide (MAPbBr₃) is a promising material that can be utilized in optoelectronic devices due to its excellent photon-electron conversion efficiency. To prevent the recombination of photogenerated electron-hole pairs during current transport, a high-quality single crystal with minimal defects is necessary. We have developed a localized thermal drive inverse temperature crystallization (LTDITC) method for MAPbBr₃ single crystal growth. The temperature distribution of the localized heat crystal growth setup was monitored with a thermal imager in specific areas during the crystal growth process. The presence of a single-phase diffraction peak and the narrow full width at half maximum (FWHM) of the (200) peak in the X-ray diffraction (XRD) pattern indicates that the crystal grown by the new LTDITC method is a high-quality single crystal. A comparison of the (200) peak FWHM for the grown crystal with that of crystals produced by the traditional oil bath method indicates a much lower defect density in the new crystal. Photoluminescence (PL) and Raman spectra reveal a narrow peak at 545 nm and 327 cm⁻¹, respectively, indicating superior crystalline quality. The new crystal’s bandgap is 2.19 eV, which is determined by a sharp UV–Vis absorption edge. Additionally, space charge limited current (SCLC) calculations reveal a low trap-state density of 6.5 × 10⁹ cm⁻³ and a carrier mobility of 64 cm² V⁻¹ s⁻¹, further confirming its exceptional optoelectronic properties.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"674 ","pages":"Article 128410"},"PeriodicalIF":2.0,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145527825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}