Pub Date : 2025-12-16DOI: 10.1016/j.jcrysgro.2025.128464
C. Stelian , P. de Marcillac , A. Giuliani , M. Velazquez
Crucial experiments to discover the origin of the neutrino mass and the nature of neutrino particles require the detection of extremely rare events, such as the neutrinoless double beta (0ν2β) decay. The core of large-scale heat-scintillation cryogenic bolometers used for the detection of such rare events will be made of hundreds of 45 mm-edge cubic Li2MoO4 (LMO) single crystals. LMO crystals of diameters close to 65 mm were grown in an optimized Czochralski (Cz) furnace configuration. Cutting a 62 mm diameter ingot revealed a radial cleavage at the top of the crystal, and a small crack located at the periphery of the bottom part of the crystal. Numerical modeling of heat transfer, convection and thermal stress in this configuration was applied to investigate these small defects, which anyway have no impact on the quality of the useful part of the ingot. Numerical results show that the thermal stress is smaller than the critical value of the tensile stress (7 MPa) over the entire crystal longitudinal section, except for a small region located at the periphery of the bottom part of the ingot. This explains the small crack observed after cutting. Numerical calculations performed for a shoulder angle greater than that in the experimental case show that the average values of the thermal stress are not significantly changed.
{"title":"Thermomechanical stresses of 6.2 cm-diameter Czochralski-grown radiopure Li2MoO4 crystals","authors":"C. Stelian , P. de Marcillac , A. Giuliani , M. Velazquez","doi":"10.1016/j.jcrysgro.2025.128464","DOIUrl":"10.1016/j.jcrysgro.2025.128464","url":null,"abstract":"<div><div>Crucial experiments to discover the origin of the neutrino mass and the nature of neutrino particles require the detection of extremely rare events, such as the neutrinoless double beta (<em>0ν2β</em>) decay. The core of large-scale heat-scintillation cryogenic bolometers used for the detection of such rare events will be made of hundreds of 45 mm-edge cubic Li<sub>2</sub>MoO<sub>4</sub> (LMO) single crystals. LMO crystals of diameters close to 65 mm were grown in an optimized Czochralski (Cz) furnace configuration. Cutting a 62 mm diameter ingot revealed a radial cleavage at the top of the crystal, and a small crack located at the periphery of the bottom part of the crystal. Numerical modeling of heat transfer, convection and thermal stress in this configuration was applied to investigate these small defects, which anyway have no impact on the quality of the useful part of the ingot. Numerical results show that the thermal stress is smaller than the critical value of the tensile stress (7 MPa) over the entire crystal longitudinal section, except for a small region located at the periphery of the bottom part of the ingot. This explains the small crack observed after cutting. Numerical calculations performed for a shoulder angle greater than that in the experimental case show that the average values of the thermal stress are not significantly changed.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128464"},"PeriodicalIF":2.0,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789271","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}
Pub Date : 2025-12-15DOI: 10.1016/j.jcrysgro.2025.128463
Gagan Kumar Chappa, Natasha Dropka
Dopant segregation in β-Ga2O3 crystals significantly compromises device performance by causing non-uniform electrical and optical properties. This study employs three-dimensional numerical simulations to investigate the effect of a traveling magnetic field (TMF) on melt homogenization during Czochralski crystal growth.
A Multiphysics framework couples heat and species transport with magnetohydrodynamics to quantify convective mixing efficiency, with a focus on solute homogenization. Various Lorentz force density fields generated by the KRIST® heaters were applied to the melt. Once the flow reached a fully developed state, a tracer was introduced to evaluate and compare stirring efficiency across the different configurations. Results indicate that TMF application substantially accelerates tracer homogenization, with the most pronounced enhancement observed at field strengths of 75–125 N/m3. In the configuration where only the crystal rotates, TMF application with a –90° phase shift reduces homogenization times by approximately 97 % (33 times) compared to baseline conditions. Similarly, in counter-rotating crystal-crucible configurations, homogenization times decreased by 63 % (2.7 times) with a +90° phase shift. These findings collectively demonstrate the feasibility of TMF application as an effective strategy for mitigating dopant segregation and enhancing crystal quality in β-Ga2O3 Czochralski growth.
{"title":"Numerical modeling of traveling magnetic fields for dopant homogenization in Czochralski β-Ga2O3 growth – a feasibility study","authors":"Gagan Kumar Chappa, Natasha Dropka","doi":"10.1016/j.jcrysgro.2025.128463","DOIUrl":"10.1016/j.jcrysgro.2025.128463","url":null,"abstract":"<div><div>Dopant segregation in β-Ga<sub>2</sub>O<sub>3</sub> crystals significantly compromises device performance by causing non-uniform electrical and optical properties. This study employs three-dimensional numerical simulations to investigate the effect of a traveling magnetic field (TMF) on melt homogenization during Czochralski crystal growth.</div><div>A Multiphysics framework couples heat and species transport with magnetohydrodynamics to quantify convective mixing efficiency, with a focus on solute homogenization. Various Lorentz force density fields generated by the KRIST<span><math><mrow><mover><mrow><mi>MAG</mi></mrow><mo>∼</mo></mover></mrow></math></span>® heaters were applied to the melt. Once the flow reached a fully developed state, a tracer was introduced to evaluate and compare stirring efficiency across the different configurations. Results indicate that TMF application substantially accelerates tracer homogenization, with the most pronounced enhancement observed at field strengths of 75–125 N/m<sup>3</sup>. In the configuration where only the crystal rotates, TMF application with a –90° phase shift reduces homogenization times by approximately 97 % (33 times) compared to baseline conditions. Similarly, in counter-rotating crystal-crucible configurations, homogenization times decreased by 63 % (2.7 times) with a +90° phase shift. These findings collectively demonstrate the feasibility of TMF application as an effective strategy for mitigating dopant segregation and enhancing crystal quality in β-Ga<sub>2</sub>O<sub>3</sub> Czochralski growth.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128463"},"PeriodicalIF":2.0,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789273","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}
Highly crystalline anatase TiO2 nanoparticles (NPs) with preferred (101) orientation were synthesized via peptization method using titanium isopropoxide (TTIP) as the precursor. The time dependent growth of anatase crystals was examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM) contributing nano beam diffraction (NBD) analysis. Average crystallite size values obtained from several standard evaluation methods verified the successful formation of nanocrystalline anatase. The crystallite size of the synthesized NPs decreases with increasing the interval of time. Rietveld refinement analysis confirmed that the NPs consisted entirely of 100 % anatase phase. The anatase exhibited a high crystallinity of 74.26 %. Enhanced crystallinity, together with the obtained crystallographic parameters, confirms the successful synthesis of highly crystalline anatase with superior properties relative to the standard material. The NPs exhibited a band gap of 3.0651 eV, indicating enhanced photocatalytic activity. A zeta potential of 75.59 mV confirmed excellent colloidal stability, while TGA revealed an activation energy (Ea) of 53.22 kJ/mole, reflecting highly reactive species. NBD revealed that the atoms were preferentially oriented along the (101) crystal plane, exhibiting bright spots on the diffracted surface and a highly preferred d-spacing of 0.358 nm. The synthesized NPs also demonstrated excellent photocatalytic performance, achieving 97.5 % degradation of crystal violet dye.
{"title":"Crystallographic integration of highly preferred orientated peptization derived nano anatase TiO2","authors":"Fariha Zannat, Md. Ashraful Alam, Raton Kumar Bishwas, Shirin Akter Jahan","doi":"10.1016/j.jcrysgro.2025.128462","DOIUrl":"10.1016/j.jcrysgro.2025.128462","url":null,"abstract":"<div><div>Highly crystalline anatase TiO<sub>2</sub> nanoparticles (NPs) with preferred (101) orientation were synthesized via peptization method using titanium isopropoxide (TTIP) as the precursor. The time dependent growth of anatase crystals was examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM) contributing nano beam diffraction (NBD) analysis. Average crystallite size values obtained from several standard evaluation methods verified the successful formation of nanocrystalline anatase. The crystallite size of the synthesized NPs decreases with increasing the interval of time. Rietveld refinement analysis confirmed that the NPs consisted entirely of 100 % anatase phase. The anatase exhibited a high crystallinity of 74.26 %. Enhanced crystallinity, together with the obtained crystallographic parameters, confirms the successful synthesis of highly crystalline anatase with superior properties relative to the standard material. The NPs exhibited a band gap of 3.0651 eV, indicating enhanced photocatalytic activity. A zeta potential of 75.59 mV confirmed excellent colloidal stability, while TGA revealed an activation energy (E<sub>a</sub>) of 53.22 kJ/mole, reflecting highly reactive species. NBD revealed that the atoms were preferentially oriented along the (101) crystal plane, exhibiting bright spots on the diffracted surface and a highly preferred d-spacing of 0.358 nm. The synthesized NPs also demonstrated excellent photocatalytic performance, achieving 97.5 % degradation of crystal violet dye.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128462"},"PeriodicalIF":2.0,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838161","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}
Pub Date : 2025-12-13DOI: 10.1016/j.jcrysgro.2025.128460
Jing Zhang , Jiahe Li , Xiang Li , Jiawei Xu , Lili Zheng , Junfeng Chen
Barium fluoride (BaF2) crystal has received significant attention in high-energy physics due to its unique sub-ns ultrafast scintillation component. Previous studies have demonstrated that slow scintillation component in BaF2 crystal can be effectively suppressed through yttrium (Y) doping. Although crack-free growth of 10 at%Y-doped BaF2 crystals with cross-sections up to 35 × 35 mm2 have been achieved, high-concentration Y-doped BaF2 crystals with large size are difficult to obtain due to cracking arising from thermal stress and mechanical stress caused by segregation of Y. This study aims to address cracking issues in Y-doped BaF2 crystals through integrated thermophysical analysis and experimental parameter optimization. Upon comparing the thermophysical properties of undoped and Y-doped BaF2 crystals, the impact of a high concentration of Y-doping was studied quantitatively, thereby establishing a criterion for thermal field tolerance. Significantly, the critical strain threshold was determined based on experimental cracking results, from which optimized parameter boundaries were derived. Through iterative experimental refinement, we successfully achieved crack-free growth of 4-inch BaF2 crystals with 15 at%Y doping. The grown crystal exhibits good optical homogeneity, maintaining > 90% transmittance across most of the visible spectrum. This parameter optimization framework demonstrates transferability for large-scale doped crystal growth systems.
{"title":"Growth and stress control of large-diameter barium fluoride crystals with heavy yttrium doping concentration for radiation detection","authors":"Jing Zhang , Jiahe Li , Xiang Li , Jiawei Xu , Lili Zheng , Junfeng Chen","doi":"10.1016/j.jcrysgro.2025.128460","DOIUrl":"10.1016/j.jcrysgro.2025.128460","url":null,"abstract":"<div><div>Barium fluoride (BaF<sub>2</sub>) crystal has received significant attention in high-energy physics due to its unique sub-ns ultrafast scintillation component. Previous studies have demonstrated that slow scintillation component in BaF<sub>2</sub> crystal can be effectively suppressed through yttrium (Y) doping. Although crack-free growth of 10 at%Y-doped BaF<sub>2</sub> crystals with cross-sections up to 35 × 35 mm<sup>2</sup> have been achieved, high-concentration Y-doped BaF<sub>2</sub> crystals with large size are difficult to obtain due to cracking arising from thermal stress and mechanical stress caused by segregation of Y. This study aims to address cracking issues in Y-doped BaF<sub>2</sub> crystals through integrated thermophysical analysis and experimental parameter optimization. Upon comparing the thermophysical properties of undoped and Y-doped BaF<sub>2</sub> crystals, the impact of a high concentration of Y-doping was studied quantitatively, thereby establishing a criterion for thermal field tolerance. Significantly, the critical strain threshold was determined based on experimental cracking results, from which optimized parameter boundaries were derived. Through iterative experimental refinement, we successfully achieved crack-free growth of 4-inch BaF<sub>2</sub> crystals with 15 at%Y doping. The grown crystal exhibits good optical homogeneity, maintaining > 90% transmittance across most of the visible spectrum. This parameter optimization framework demonstrates transferability for large-scale doped crystal growth systems.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128460"},"PeriodicalIF":2.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789274","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}
Pub Date : 2025-12-13DOI: 10.1016/j.jcrysgro.2025.128459
A. Lankinen , T.O. Tuomi , O. Anttila , S. Sintonen , P. Kostamo , P.J. McNally , C. Paulmann
Geometric analysis of synchrotron X-ray topographs of samples cut from heavily arsenic doped silicon crystal neck were used for the determination of the directions and the Burgers vectors of dislocations, which revealed their type. Straight dislocation lines in heavily As-doped silicon neck were observed in addition to easily eliminated half-loop dislocations. The straight dislocations were more resilient and disappeared later during the neck growth. Growth of a structural crystal body proved that the neck was dislocation free, but the straight dislocations associated with the heavy As-doping likely necessitate a longer neck growth than could be used in lightly doped silicon crystals.
{"title":"Synchrotron X-ray topography investigation on dislocation propagation in heavily arsenic-doped silicon crystal necks","authors":"A. Lankinen , T.O. Tuomi , O. Anttila , S. Sintonen , P. Kostamo , P.J. McNally , C. Paulmann","doi":"10.1016/j.jcrysgro.2025.128459","DOIUrl":"10.1016/j.jcrysgro.2025.128459","url":null,"abstract":"<div><div>Geometric analysis of synchrotron X-ray topographs of samples cut from heavily arsenic doped silicon crystal neck were used for the determination of the directions and the Burgers vectors of dislocations, which revealed their type. Straight dislocation lines in heavily As-doped silicon neck were observed in addition to easily eliminated half-loop dislocations. The straight dislocations were more resilient and disappeared later during the neck growth. Growth of a structural crystal body proved that the neck was dislocation free, but the straight dislocations associated with the heavy As-doping likely necessitate a longer neck growth than could be used in lightly doped silicon crystals.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128459"},"PeriodicalIF":2.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789275","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}
Oxide crystal growth from cold crucible was applied to trial enlargement of β-Ga2O3 single crystals in both diameter and length. Using a 150-mm Cu basket with automatic diameter control, stable seeding, necking, and shoulder formation were achieved. Consequently, single crystals with diameters of up to 32 mm and body lengths of 50.8 mm (2 in.) were successfully obtained, demonstrating considerable progress in crystal scaling. X-ray rocking curve analysis confirmed the full width at half maximum values, which were comparable to those of edge-defined film-fed growth substrates. Glow discharge mass spectrometry revealed no trace of Ir, Pt, and Rh impurities. These findings highlight the oxide crystal growth from cold crucible as a scalable, contamination-free, and cost-effective method for producing large β-Ga2O3 crystals, advancing their potential for power electronic applications.
{"title":"β-Ga2O3 crystal growth with cold container crucibles: Large-scale oxide crystal growth from cold crucible method","authors":"Masanori Kitahara , Taketoshi Tomida , Vladimir Kochurikhin , Gushchina Liudmila , Kei Kamada , Yasuhiro Shoji , Koichi Kakimoto , Akira Yoshikawa","doi":"10.1016/j.jcrysgro.2025.128461","DOIUrl":"10.1016/j.jcrysgro.2025.128461","url":null,"abstract":"<div><div>Oxide crystal growth from cold crucible was applied to trial enlargement of β-Ga<sub>2</sub>O<sub>3</sub> single crystals in both diameter and length. Using a 150-mm Cu basket with automatic diameter control, stable seeding, necking, and shoulder formation were achieved. Consequently, single crystals with diameters of up to 32 mm and body lengths of 50.8 mm (2 in.) were successfully obtained, demonstrating considerable progress in crystal scaling. X-ray rocking curve analysis confirmed the full width at half maximum values, which were comparable to those of edge-defined film-fed growth substrates. Glow discharge mass spectrometry revealed no trace of Ir, Pt, and Rh impurities. These findings highlight the oxide crystal growth from cold crucible as a scalable, contamination-free, and cost-effective method for producing large β-Ga<sub>2</sub>O<sub>3</sub> crystals, advancing their potential for power electronic applications.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128461"},"PeriodicalIF":2.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789272","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}
Pub Date : 2025-12-09DOI: 10.1016/j.jcrysgro.2025.128456
Bing Yan, Weihua Liu, Chang Yu, Pandeng Gao, Tuanjie Liang, Kaifeng Liao, Biru Jiang, Tiantai Wang, Fan Liu, Hongyu Liang, Kun Feng, Li Huang
CdZnTe (CZT) is an ideal substrate for growing HgCdTe (MCT) epitaxial layers in infrared devices. A convex growth interface is desired but is typically difficult to form during the Bridgman process of CZT crystals owing to their low thermal conductivity. Obtaining high-quality CZT single crystals with high yields remains a challenge. This study proposes a method for achieving a slightly convex interface during the CZT crystal growth process. The presence of the slightly convex interface is confirmed via Zn component mapping calibration. Single crystals were reproducibly obtained using this method, improving the crystal quality of CZT for high-performance device applications. The obtained CZT crystals were characterized via optical microscopy, infrared transmission microscopy, high-resolution X-ray diffraction, X-ray tomography (XRT), and Fourier transform infrared spectroscopy. The etch pit density of (111)-B (tellurium-polar face) CZT sliced wafers was < 4.0 × 103 cm−2. For the double-grinding wafers, the Te inclusions in the CZT volume of were sparsely distributed, and their sizes could be controlled to < 5 μm. The typical full width at half maximum of the Bragg diffraction peaks was < 18″. A uniform XRT image of (111)-B CZT polished wafers was obtained. The responsivity of the prepared mid-wave 640 × 512 MCT FPA final image was uniform, with no noticeable electro-optical clustering. Additionally, the noise-equivalent temperature difference was measured to be 14.5 mK, indicating the high quality of the as-grown CZT crystals. This study provides useful guidelines for CZT crystals growth and a promising method for reducing the current cost of commercial CZT substrates.
{"title":"Optimizing growth interface shape in CdZnTe single crystal growth using vertical Bridgman method","authors":"Bing Yan, Weihua Liu, Chang Yu, Pandeng Gao, Tuanjie Liang, Kaifeng Liao, Biru Jiang, Tiantai Wang, Fan Liu, Hongyu Liang, Kun Feng, Li Huang","doi":"10.1016/j.jcrysgro.2025.128456","DOIUrl":"10.1016/j.jcrysgro.2025.128456","url":null,"abstract":"<div><div>CdZnTe (CZT) is an ideal substrate for growing HgCdTe (MCT) epitaxial layers in infrared devices. A convex growth interface is desired but is typically difficult to form during the Bridgman process of CZT crystals owing to their low thermal conductivity. Obtaining high-quality CZT single crystals with high yields remains a challenge. This study proposes a method for achieving a slightly convex interface during the CZT crystal growth process. The presence of the slightly convex interface is confirmed via Zn component mapping calibration. Single crystals were reproducibly obtained using this method, improving the crystal quality of CZT for high-performance device applications. The obtained CZT crystals were characterized via optical microscopy, infrared transmission microscopy, high-resolution X-ray diffraction, X-ray tomography (XRT), and Fourier transform infrared spectroscopy. The etch pit density of (111)-B (tellurium-polar face) CZT sliced wafers was < 4.0 × 10<sup>3</sup> cm<sup>−2</sup>. For the double-grinding wafers, the Te inclusions in the CZT volume of were sparsely distributed, and their sizes could be controlled to < 5 μm. The typical full width at half maximum of the Bragg diffraction peaks was < 18″. A uniform XRT image of (111)-B CZT polished wafers was obtained. The responsivity of the prepared mid-wave 640 × 512 MCT FPA final image was uniform, with no noticeable electro-optical clustering. Additionally, the noise-equivalent temperature difference was measured to be 14.5 mK, indicating the high quality of the as-grown CZT crystals. This study provides useful guidelines for CZT crystals growth and a promising method for reducing the current cost of commercial CZT substrates.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128456"},"PeriodicalIF":2.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733896","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}
Pub Date : 2025-12-09DOI: 10.1016/j.jcrysgro.2025.128458
Zhuochen Duan , Hua Wei , Dingzhang Wu , Junhong Lv , Tinglong Liu , Xueqiang Wu , Hanbao Liu , Feng Lin , Jie Yang , Feng Qiu , Shikun Pu , Feng Hui , Chong Wang
Owing to its advantages of a small axial temperature gradient and high-precision thermal field control, the Vertical Gradient Freeze (VGF) method has emerged as a mainstream technique for industrial InP single crystal growth. However, during the growth of large-sized InP crystal via VGF, defects such as twins and dislocations frequently form at the shouldering stage due to rapid crystallization area expansion, non-uniform latent heat release, and loss of control over the solid–liquid interface shape at the crystallization front. This study establishes a finite element-based physical model for 4.5-inch InP single crystal growth under unsteady thermal fields. Based on systematic growth parameter regulation and heat-transfer structure optimization, the evolution of the solid–liquid interface shape is investigated during the whole growth process. Calculated results indicate that for large-diameter crystals, the key to achieving a planar solid–liquid interface lies in adopting a slower growth rate and a lower axial temperature gradient. Under current heat exchange conditions, the crystal growth interface undergoes a dynamic evolution along the ingot axis, typically transitioning from slightly convex to relatively flat, and finally to slightly concave. Consequently, a set of thermal field structure for optimizing axial heat distribution are designed and implemented in single-crystal growth experiments. Our experimental results demonstrate consistency with the simulation, showing that the solid–liquid interface maintains a prolonged slightly convex shape in shouldering growth then shifts to a slightly concave profile in equal-diameter growth Consequently, the statistical probability of twin formation in these InP ingots undergone heat-field optimization decreases by approximately 20 % compared to those with the current-adopted heat-field.
{"title":"A study on solid–liquid interface shape optimization and dislocation suppression for 4.5-inch InP single crystal growth based on vertical gradient freezing technique","authors":"Zhuochen Duan , Hua Wei , Dingzhang Wu , Junhong Lv , Tinglong Liu , Xueqiang Wu , Hanbao Liu , Feng Lin , Jie Yang , Feng Qiu , Shikun Pu , Feng Hui , Chong Wang","doi":"10.1016/j.jcrysgro.2025.128458","DOIUrl":"10.1016/j.jcrysgro.2025.128458","url":null,"abstract":"<div><div>Owing to its advantages of a small axial temperature gradient and high-precision thermal field control, the Vertical Gradient Freeze (VGF) method has emerged as a mainstream technique for industrial InP single crystal growth. However, during the growth of large-sized InP crystal via VGF, defects such as twins and dislocations frequently form at the shouldering stage due to rapid crystallization area expansion, non-uniform latent heat release, and loss of control over the solid–liquid interface shape at the crystallization front. This study establishes a finite element-based physical model for 4.5-inch InP single crystal growth under unsteady thermal fields. Based on systematic growth parameter regulation and heat-transfer structure optimization, the evolution of the solid–liquid interface shape is investigated during the whole growth process. Calculated results indicate that for large-diameter crystals, the key to achieving a planar solid–liquid interface lies in adopting a slower growth rate and a lower axial temperature gradient. Under current heat exchange conditions, the crystal growth interface undergoes a dynamic evolution along the ingot axis, typically transitioning from slightly convex to relatively flat, and finally to slightly concave. Consequently, a set of thermal field structure for optimizing axial heat distribution are designed and implemented in single-crystal growth experiments. Our experimental results demonstrate consistency with the simulation, showing that the solid–liquid interface maintains a prolonged slightly convex shape in shouldering growth then shifts to a slightly concave profile in equal-diameter growth Consequently, the statistical probability of twin formation in these InP ingots undergone heat-field optimization decreases by approximately 20 % compared to those with the current-adopted heat-field.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128458"},"PeriodicalIF":2.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733899","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}
Pub Date : 2025-12-09DOI: 10.1016/j.jcrysgro.2025.128457
Daseul Ham , Seonghyun Han , Su Yong Lee , Jihye Seo , Do Young Noh , Hyon Chol Kang
We investigated the crystallization behavior and structural evolution of amorphous Ga2O3 thin films deposited on sapphire (0001) substrates via solid phase epitaxy (SPE) using a synchrotron-based in-situ multimodal X-ray probe station. Real-time X-ray diffraction (XRD) and electrical conductance measurements during post-annealing revealed that crystallization into the α-Ga2O3 phase begins at approximately 500 °C, accompanied by a marked increase in conductance owing to thermally activated carrier transport. High-resolution XRD confirmed the formation of a high-quality α-Ga2O3 film with the c-axis oriented along the surface normal and fully relaxed lattice parameters in the in-plane and out-of-plane directions. Azimuthal angle scans revealed six-fold symmetry, confirming epitaxial in-plane alignment between the α-Ga2O3 film and sapphire (0001) substrate. Rocking curve analysis yielded dislocation densities of ∼1.07 × 108 (screw) and ∼4.34 × 109 cm−2 (edge), corresponding to a total threading dislocation density of approximately 4.45 × 109 cm−2, which is comparable to previously reported values for directly grown α-Ga2O3 films. These findings demonstrate that SPE is a promising alternative to conventional epitaxy for producing high-quality α-Ga2O3 thin films. This approach enables phase-selective crystallization with excellent structural quality, without the need for high-temperature deposition or complex substrate engineering, thereby offering a viable pathway for integration into thermally sensitive device platforms.
{"title":"Solid-phase crystallization of amorphous Ga2O3/sapphire(0001) thin films monitored using in-situ multimodal X-ray probe technique","authors":"Daseul Ham , Seonghyun Han , Su Yong Lee , Jihye Seo , Do Young Noh , Hyon Chol Kang","doi":"10.1016/j.jcrysgro.2025.128457","DOIUrl":"10.1016/j.jcrysgro.2025.128457","url":null,"abstract":"<div><div>We investigated the crystallization behavior and structural evolution of amorphous Ga<sub>2</sub>O<sub>3</sub> thin films deposited on sapphire (0001) substrates via solid phase epitaxy (SPE) using a synchrotron-based <em>in-situ</em> multimodal X-ray probe station. Real-time X-ray diffraction (XRD) and electrical conductance measurements during post-annealing revealed that crystallization into the α-Ga<sub>2</sub>O<sub>3</sub> phase begins at approximately 500 °C, accompanied by a marked increase in conductance owing to thermally activated carrier transport. High-resolution XRD confirmed the formation of a high-quality α-Ga<sub>2</sub>O<sub>3</sub> film with the <em>c</em>-axis oriented along the surface normal and fully relaxed lattice parameters in the in-plane and out-of-plane directions. Azimuthal angle scans revealed six-fold symmetry, confirming epitaxial in-plane alignment between the α-Ga<sub>2</sub>O<sub>3</sub> film and sapphire (0001) substrate. Rocking curve analysis yielded dislocation densities of ∼1.07 × 10<sup>8</sup> (screw) and ∼4.34 × 10<sup>9</sup> cm<sup>−2</sup> (edge), corresponding to a total threading dislocation density of approximately 4.45 × 10<sup>9</sup> cm<sup>−2</sup>, which is comparable to previously reported values for directly grown α-Ga<sub>2</sub>O<sub>3</sub> films. These findings demonstrate that SPE is a promising alternative to conventional epitaxy for producing high-quality α-Ga<sub>2</sub>O<sub>3</sub> thin films. This approach enables phase-selective crystallization with excellent structural quality, without the need for high-temperature deposition or complex substrate engineering, thereby offering a viable pathway for integration into thermally sensitive device platforms.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128457"},"PeriodicalIF":2.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733901","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}
Pub Date : 2025-12-09DOI: 10.1016/j.jcrysgro.2025.128454
Wenjie Zhang , Qisheng Chen , Qinhua Wei , Hang Yin , Gao Tang , Suyin Zhang , Xilei Sun , Yanliang Liu , Laishun Qin
Cs3Cu2I5 single crystals are considered excellent scintillators and semiconductors for indirect and direct X-ray detection. In this paper, the strategy of heterovalent ion (Sr2+) doping was adopted to improve X-ray detection properties further. High-quality pure Cs3Cu2I5 and Sr-doped Cs3Cu2I5 single crystals were grown by the Bridgman method. The crystal structure and doping concentration was characterized using XRD, XPS and ICP-MS. The carrier mobility was increased from 0.063 cm2/Vs to 3.524 cm2/Vs while the sensitivity and detection limit of crystal were improved by doping with Sr2+. The properties of direct X-ray detection were improved while the PLQY, scintillation light yield, and energy resolution were all decreased. The defect and activation energies were investigated by thermoluminescence (TL) and variable temperature XEL. Finally, the mechanism is also discussed. The doping of Sr2+ is an effective method to tuning the performance of direct X-ray detection.
{"title":"Effects of Sr2+ doping on the X-ray detection properties of Cs3Cu2I5 crystal","authors":"Wenjie Zhang , Qisheng Chen , Qinhua Wei , Hang Yin , Gao Tang , Suyin Zhang , Xilei Sun , Yanliang Liu , Laishun Qin","doi":"10.1016/j.jcrysgro.2025.128454","DOIUrl":"10.1016/j.jcrysgro.2025.128454","url":null,"abstract":"<div><div>Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> single crystals are considered excellent scintillators and semiconductors for indirect and direct X-ray detection. In this paper, the strategy of heterovalent ion (Sr<sup>2+</sup>) doping was adopted to improve X-ray detection properties further. High-quality pure Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> and Sr-doped Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> single crystals were grown by the Bridgman method. The crystal structure and doping concentration was characterized using XRD, XPS and ICP-MS. The carrier mobility was increased from 0.063 cm<sup>2</sup>/Vs to 3.524 cm<sup>2</sup>/Vs while the sensitivity and detection limit of crystal were improved by doping with Sr<sup>2+</sup>. The properties of direct X-ray detection were improved while the PLQY, scintillation light yield, and energy resolution were all decreased. The defect and activation energies were investigated by thermoluminescence (TL) and variable temperature XEL. Finally, the mechanism is also discussed. The doping of Sr<sup>2+</sup> is an effective method to tuning the performance of direct X-ray detection.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128454"},"PeriodicalIF":2.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733898","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}
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