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}
Pub Date : 2025-12-07DOI: 10.1016/j.jcrysgro.2025.128455
Haram Lee, Mijin Park, Hyon Chol Kang
This study investigates the structural and optical evolution of Sn-doped Ga2O3 thin films as a function of Sn content. The films were grown on sapphire (0001) substrates using radio-frequency powder sputtering with a mixture of SnO2 and Ga2O3 powders at 600 °C. X-ray diffraction and transmission electron microscopy revealed a clear crystalline-to-amorphous transition with increasing Sn concentration. The films with a low Sn content exhibited a mixed structure comprising columnar crystalline grains and conical amorphous regions. At higher Sn concentrations (up to 9.23 at%), the films became entirely amorphous, except for a thin crystalline layer near the substrate interface. This transition was driven by excessive lattice distortion and Sn incorporation beyond the solubility threshold. Ultraviolet–visible absorption spectroscopy showed a monotonic decrease in the optical bandgap from 5.1 eV (undoped) to 4.88 eV (9.23 at% Sn-doped), attributed to amorphization-induced disorder and the formation of localized states near the band edges. These results highlight the role of Sn doping in the phase stability and electronic properties of Ga2O3 thin films.
本文研究了掺锡Ga2O3薄膜的结构和光学演化与Sn含量的关系。采用SnO2和Ga2O3混合粉末在600℃下射频粉末溅射的方法在蓝宝石（0001）衬底上生长薄膜。x射线衍射和透射电镜显示，随着锡浓度的增加，晶体向非晶态转变明显。低锡含量的薄膜呈现柱状晶粒和锥形非晶态混合结构。在较高的Sn浓度（高达9.23 At %）下，薄膜除了在衬底界面附近有一层薄晶层外，完全变成无定形。这种转变是由过度的晶格畸变和Sn掺入超过溶解度阈值驱动的。紫外-可见吸收光谱显示，光学带隙从5.1 eV（未掺杂）单调减小到4.88 eV（掺杂% sn时为9.23 eV），这是由于非晶化引起的无序和带边缘附近局域态的形成。这些结果突出了Sn掺杂对Ga2O3薄膜相稳定性和电子性能的影响。
{"title":"Crystalline-to-amorphous transition in Sn-doped Ga2O3 thin films grown by radio-frequency powder sputtering","authors":"Haram Lee, Mijin Park, Hyon Chol Kang","doi":"10.1016/j.jcrysgro.2025.128455","DOIUrl":"10.1016/j.jcrysgro.2025.128455","url":null,"abstract":"<div><div>This study investigates the structural and optical evolution of Sn-doped Ga<sub>2</sub>O<sub>3</sub> thin films as a function of Sn content. The films were grown on sapphire (0001) substrates using radio-frequency powder sputtering with a mixture of SnO<sub>2</sub> and Ga<sub>2</sub>O<sub>3</sub> powders at 600 °C. X-ray diffraction and transmission electron microscopy revealed a clear crystalline-to-amorphous transition with increasing Sn concentration. The films with a low Sn content exhibited a mixed structure comprising columnar crystalline grains and conical amorphous regions. At higher Sn concentrations (up to 9.23 at%), the films became entirely amorphous, except for a thin crystalline layer near the substrate interface. This transition was driven by excessive lattice distortion and Sn incorporation beyond the solubility threshold. Ultraviolet–visible absorption spectroscopy showed a monotonic decrease in the optical bandgap from 5.1 eV (undoped) to 4.88 eV (9.23 at% Sn-doped), attributed to amorphization-induced disorder and the formation of localized states near the band edges. These results highlight the role of Sn doping in the phase stability and electronic properties of Ga<sub>2</sub>O<sub>3</sub> thin films.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128455"},"PeriodicalIF":2.0,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733897","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}
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.
{"title":"Machine learning framework for derivation and optimization of Cz-YAG crystal growth recipe","authors":"Kunal Meshram , Milena Petkovic , Martin Holena , 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":"2025-12-05","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}
Pub Date : 2025-12-05DOI: 10.1016/j.jcrysgro.2025.128453
Mustafa Biçer
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 (Jsc) and lowest charge transfer resistance (Rct), 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.
{"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 (S<sub>1</sub>), ZnO-SnO heteronanostructures (HNSs) (S<sub>2</sub> and S<sub>3</sub>), and SnO (S<sub>4</sub>) 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 S<sub>2</sub>-based cell had the highest short-circuit current density (J<sub>sc</sub>) and lowest charge transfer resistance (R<sub>ct</sub>), 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":"2025-12-05","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}
We grew highly tin- (Sn-) doped germanium (Ge) crystals using the Czochralski technique. Full single crystals with a maximum Sn concentration of approximately 1020 cm−3 were obtained. Variations in the Sn concentration of the grown crystals were well reproduced based on the Scheil-Pfann relation, which has a segregation coefficient of k = 0.02. Sn precipitates were formed during the cooling stage after the solidification. In Ge and silicon (Si), the segregation coefficients of Sn and other impurities exhibit a distinctive relationship with respect to the volume misfit strain, wherein the segregation coefficient decreases as the volume misfit strain increases. We discuss a design to increase the dopant concentration by co-doping Sn into Ge. An increase in the Sn fraction is expected in the Si-rich SiGe alloy.
{"title":"Growth of tin-doped Ge crystals: A comparison of impurity segregation behavior with IV element crystals and alloys","authors":"Ichiro Yonenaga , Toshinori Taishi , Yu Murao , Kaihei Inoue","doi":"10.1016/j.jcrysgro.2025.128452","DOIUrl":"10.1016/j.jcrysgro.2025.128452","url":null,"abstract":"<div><div>We grew highly tin- (Sn-) doped germanium (Ge) crystals using the Czochralski technique. Full single crystals with a maximum Sn concentration of approximately 10<sup>20</sup> cm<sup>−3</sup> were obtained. Variations in the Sn concentration of the grown crystals were well reproduced based on the Scheil-Pfann relation, which has a segregation coefficient of <em>k</em> = 0.02. Sn precipitates were formed during the cooling stage after the solidification. In Ge and silicon (Si), the segregation coefficients of Sn and other impurities exhibit a distinctive relationship with respect to the volume misfit strain, wherein the segregation coefficient decreases as the volume misfit strain increases. We discuss a design to increase the dopant concentration by co-doping Sn into Ge. An increase in the Sn fraction is expected in the Si-rich SiGe alloy.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128452"},"PeriodicalIF":2.0,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733900","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 : 2025-12-02DOI: 10.1016/j.jcrysgro.2025.128450
P. Kleinschmidt , D. Bratek , M. Nandy , J. Koch , V.S. Chejarla , A. Beyer , K.D. Hanke , K. Volz , A. Paszuk , T. Hannappel
The epitaxy of III-V semiconductors on Si(1 0 0) is typically associated with the formation of antiphase domains within the III-V layer. The associated antiphase boundaries constitute planar defects that must be avoided in high-performance devices, or at least prevented from extending into the active region of the device. Here, we present top-view, atomically resolved STM images of thin GaP layers deposited by metalorganic chemical vapor deposition on an As-containing Si(1 0 0) surface. We verify the atomic surface structure, clearly identify phase and antiphase at the surface, and provide high-resolution images of the antiphase boundaries. We show that these boundaries are far from ideal, and are associated with kinks, trenches, and many defects, in particular at the corners of the boundaries. Our work underlines the detrimental effect of the antiphase boundaries, and therefore the necessity for the underlying Si(1 0 0) substrate to be prepared with a near-single-domain surface to avoid antiphase domains in the III-V layer.
{"title":"Atomic surface structure of antiphase domains in heteroepitaxial GaP films grown on arsenic-terminated Si(100)","authors":"P. Kleinschmidt , D. Bratek , M. Nandy , J. Koch , V.S. Chejarla , A. Beyer , K.D. Hanke , K. Volz , A. Paszuk , T. Hannappel","doi":"10.1016/j.jcrysgro.2025.128450","DOIUrl":"10.1016/j.jcrysgro.2025.128450","url":null,"abstract":"<div><div>The epitaxy of III-V semiconductors on Si(1<!--> <!-->0<!--> <!-->0) is typically associated with the formation of antiphase domains within the III-V layer. The associated antiphase boundaries constitute planar defects that must be avoided in high-performance devices, or at least prevented from extending into the active region of the device. Here, we present top-view, atomically resolved STM images of thin GaP layers deposited by metalorganic chemical vapor deposition on an As-containing Si(1<!--> <!-->0<!--> <!-->0) surface. We verify the atomic surface structure, clearly identify phase and antiphase at the surface, and provide high-resolution images of the antiphase boundaries. We show that these boundaries are far from ideal, and are associated with kinks, trenches, and many defects, in particular at the corners of the boundaries. Our work underlines the detrimental effect of the antiphase boundaries, and therefore the necessity for the underlying Si(1<!--> <!-->0<!--> <!-->0) substrate to be prepared with a near-single-domain surface to avoid antiphase domains in the III-V layer.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"677 ","pages":"Article 128450"},"PeriodicalIF":2.0,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145750043","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 : 2025-11-30DOI: 10.1016/j.jcrysgro.2025.128447
Ziyue Chen, Rukang Li
A new lanthanum niobium tellurite LaNbTe2O8, with favorable mid-infrared (IR) NLO properties has been obtained by high-temperature solution method using excess amount of TeO2 as flux. This compound crystallized in the noncentrosymmetric space group Abm2 with unit cell parameters of a = 10.9602(14) Å, b = 7.8406(9) Å, c = 8.1507(9) Å and Z = 4. Its structure features two alternate arranged layers consisting of highly distorted NbO6 octahedra and LaO8 polyhedra, and TeO3 trigonal pyramids with stereoactive lone pairs connect the layers to complete the 3D framework. Notably, the optical measurements revealed that LaNbTe2O8 possesses a strong second harmonic generation (SHG) signal of 1.2 × KTP at 1064 nm and a wide transparent range (0.34−5.6 μm), which could cover the full crucial atmospheric window (3–5 μm). Considering its large birefringence of 0.165 as revealed by the calculations, it should be capable of realizing phase matching conditions in a wide range. These properties make LaNbTe2O8 a potential candidate as a mid-IR nonlinear optical material.
以过量的TeO2为助熔剂，采用高温溶液法制备了具有良好中红外（IR） NLO性能的新型碲铌镧镧te2o8。该化合物在非中心对称空间群Abm2中结晶，晶胞参数为a = 10.9602（14） Å， b = 7.8406(9) Å， c = 8.1507(9) Å， Z = 4。其结构特点是由高度扭曲的NbO6八面体和la8多面体组成的两个交替排列的层，具有立体活性的TeO3三角形金字塔将层连接起来，形成完整的三维框架。值得注意的是，光学测量表明，LaNbTe2O8在1064 nm处具有1.2 × KTP的强二次谐波产生（SHG）信号和宽的透明范围（0.34 ~ 5.6 μm），可以覆盖整个关键大气窗口（3-5 μm）。计算表明，它的双折射大，为0.165，因此应该能够在大范围内实现相位匹配条件。这些特性使LaNbTe2O8成为中红外非线性光学材料的潜在候选材料。
{"title":"LaNbTe2O8: A mid-infrared nonlinear optical crystal exhibiting strong second harmonic generation effect and notable birefringence","authors":"Ziyue Chen, Rukang Li","doi":"10.1016/j.jcrysgro.2025.128447","DOIUrl":"10.1016/j.jcrysgro.2025.128447","url":null,"abstract":"<div><div>A new lanthanum niobium tellurite LaNbTe<sub>2</sub>O<sub>8</sub>, with favorable mid-infrared (IR) NLO properties has been obtained by high-temperature solution method using excess amount of TeO<sub>2</sub> as flux. This compound crystallized in the noncentrosymmetric space group <em>A</em>bm2 with unit cell parameters of <em>a</em> = 10.9602(14) Å, <em>b</em> = 7.8406(9) Å, <em>c</em> = 8.1507(9) Å and <em>Z</em> = 4. Its structure features two alternate arranged layers consisting of highly distorted NbO<sub>6</sub> octahedra and LaO<sub>8</sub> polyhedra, and TeO<sub>3</sub> trigonal pyramids with stereoactive lone pairs connect the layers to complete the 3D framework. Notably, the optical measurements revealed that LaNbTe<sub>2</sub>O<sub>8</sub> possesses a strong second harmonic generation (SHG) signal of 1.2 × KTP at 1064 nm and a wide transparent range (0.34−5.6 μm), which could cover the full crucial atmospheric window (3–5 μm). Considering its large birefringence of 0.165 as revealed by the calculations, it should be capable of realizing phase matching conditions in a wide range. These properties make LaNbTe<sub>2</sub>O<sub>8</sub> a potential candidate as a mid-IR nonlinear optical material.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128447"},"PeriodicalIF":2.0,"publicationDate":"2025-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682808","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}
The high-purity preparation of gallium (Ga) faces bottlenecks such as low purification efficiency and lengthy processing steps. This study innovatively proposes the introduction of magnetically controlled flow during the directional crystallization purification of Ga. This magnetically controlled technique more than doubles the purification efficiency, achieving a purity of 11.629 ppm in only two passes compared to the 11.843 ppm obtained by the conventional method in six passes. The underlying mechanism for this enhancement lies in the fact that the magnetically controlled flow promotes the migration of impurities at the solidification front, reduces the thickness of the solute boundary layer, and lowers the effective distribution coefficient, thereby significantly increasing purification efficiency. This magnetically controlled purification technique offers a new approach for efficient production of high-purity and even ultra-high-purity Ga, and can be further extended to the purification of other metals.
{"title":"Over two-fold purification efficiency improvement via magnetically controlled directional crystallization of Ga","authors":"Zhe Shen, Dewei Xun, Meng Sun, Biao Ding, Zhongze Lin, Tianxiang Zheng, Bangfei Zhou, Yunbo Zhong","doi":"10.1016/j.jcrysgro.2025.128449","DOIUrl":"10.1016/j.jcrysgro.2025.128449","url":null,"abstract":"<div><div>The high-purity preparation of gallium (Ga) faces bottlenecks such as low purification efficiency and lengthy processing steps. This study innovatively proposes the introduction of magnetically controlled flow during the directional crystallization purification of Ga. This magnetically controlled technique more than doubles the purification efficiency, achieving a purity of 11.629 ppm in only two passes compared to the 11.843 ppm obtained by the conventional method in six passes. The underlying mechanism for this enhancement lies in the fact that the magnetically controlled flow promotes the migration of impurities at the solidification front, reduces the thickness of the solute boundary layer, and lowers the effective distribution coefficient, thereby significantly increasing purification efficiency. This magnetically controlled purification technique offers a new approach for efficient production of high-purity and even ultra-high-purity Ga, and can be further extended to the purification of other metals.</div><div><strong>Kewwords:</strong> High-purity gallium; Directional crystallization; Magnetically controlled flow; Effective distribution coefficient; Solute boundary layer.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128449"},"PeriodicalIF":2.0,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682805","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 : 2025-11-29DOI: 10.1016/j.jcrysgro.2025.128448
Weimin Dong , Henghao Feng , Xin Zhao , Linwei Song , Jin Yang , Dazheng Deng , Yingjie Sun , Biwen Duan , Shufen Li , Deliang Chu , Qianwen Peng , Yumin Li , Jincheng Kong , Jun Zhao
Twinning is a critical factor limiting the size and yield of III-V semiconductor single crystals. In this work, the < 100 > GaSb crystals were grown by the liquid-encapsulated Czochralski (LEC) method, and the influences of dislocations and {111} facets on twinning were studied. During the seeding and shouldering, the low-angle grain boundaries resulting from dislocation multiplication typically induce twinning or polycrystallization. Moreover, when growing < 100 > GaSb crystals, twinning tends to occur preferentially on the ()Sb plane. First-principles calculations revealed that the stacking fault energy (SFE) of the ()Sb plane (25.36 mJ/m2) is much smaller than that of the (111)Ga plane (54.25 mJ/m2), indicating a higher propensity for twin nucleation on the ()Sb plane, thereby confirming the experimental observations. The experimental results show that at the solid–liquid growth interface, the supercooling(ΔT) near the ()Sb plane is significantly higher than on the (111)Ga plane, which leads to a considerably greater probability of twinning nucleation occurring on the ()Sb plane. The abrupt increase in ΔT caused by local temperature fluctuations may be the primary reason for twinning in < 100 > GaSb crystals.
{"title":"Study on the twinning in LEC-GaSb crystals","authors":"Weimin Dong , Henghao Feng , Xin Zhao , Linwei Song , Jin Yang , Dazheng Deng , Yingjie Sun , Biwen Duan , Shufen Li , Deliang Chu , Qianwen Peng , Yumin Li , Jincheng Kong , Jun Zhao","doi":"10.1016/j.jcrysgro.2025.128448","DOIUrl":"10.1016/j.jcrysgro.2025.128448","url":null,"abstract":"<div><div>Twinning is a critical factor limiting the size and yield of III-V semiconductor single crystals. In this work, the < 100 > GaSb crystals were grown by the liquid-encapsulated Czochralski (LEC) method, and the influences of dislocations and {111} facets on twinning were studied. During the seeding and shouldering, the low-angle grain boundaries resulting from dislocation multiplication typically induce twinning or polycrystallization. Moreover, when growing < 100 > GaSb crystals, twinning tends to occur preferentially on the (<span><math><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span>)Sb plane. First-principles calculations revealed that the stacking fault energy (SFE) of the (<span><math><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span>)Sb plane (25.36 mJ/m<sup>2</sup>) is much smaller than that of the (111)Ga plane (54.25 mJ/m<sup>2</sup>), indicating a higher propensity for twin nucleation on the (<span><math><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span>)Sb plane, thereby confirming the experimental observations. The experimental results show that at the solid–liquid growth interface, the supercooling(Δ<em>T</em>) near the (<span><math><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span>)Sb plane is significantly higher than on the (111)Ga plane, which leads to a considerably greater probability of twinning nucleation occurring on the (<span><math><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span>)Sb plane. The abrupt increase in Δ<em>T</em> caused by local temperature fluctuations may be the primary reason for twinning in < 100 > GaSb crystals.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"676 ","pages":"Article 128448"},"PeriodicalIF":2.0,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682803","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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