Pub Date : 2026-01-26DOI: 10.1016/j.jcrysgro.2026.128505
Haifeng Chen , Zijie Ding , Chunling Chen , Xuyang Liu , Xiexin Sun , Zhihong Wei , Jun Ma , Yifan Jia , Yue Hao
In this work, ultra-large β-Ga2O3 nanobelts with millimeter-long and hundreds-of-micron-wide dimensions are synthesized using the carbon thermal reduction method. The maximum width of nanobelts is 352 μm. The nanobelts are of high-purity β phase with a thickness of approximately 65 nm, and their surface is defect-free and smooth with a root mean square roughness of 370 pm. The optimal growth direction of nanobelt is [010], and the easy cleavage planes are ( 12) and ( 2). Based on the nanobelts, multi-MOSFET device process integration is carried out, and a 150 × 150 μm2 source/drain electrode placement is achieved on a 165 μm-wide nanobelt. The dark drain current is extremely low of about 10-13 A. Under the 254 nm solar-blind UV light, MOSFET exhibits the excellent gate control characteristics. This study highlights the significant application potential of the distinctive crystal morphology of β-Ga2O3 nanobelts in future microelectronics.
{"title":"Ultra-large β-Ga2O3 nanobelt and nanobelt-based multi-MOSFET integration","authors":"Haifeng Chen , Zijie Ding , Chunling Chen , Xuyang Liu , Xiexin Sun , Zhihong Wei , Jun Ma , Yifan Jia , Yue Hao","doi":"10.1016/j.jcrysgro.2026.128505","DOIUrl":"10.1016/j.jcrysgro.2026.128505","url":null,"abstract":"<div><div>In this work, ultra-large β-Ga<sub>2</sub>O<sub>3</sub> nanobelts with millimeter-long and hundreds-of-micron-wide dimensions are synthesized using the carbon thermal reduction method. The maximum width of nanobelts is 352 μm. The nanobelts are of high-purity β phase with a thickness of approximately 65 nm, and their surface is defect-free and smooth with a root mean square roughness of 370 pm. The optimal growth direction of nanobelt is [010], and the easy cleavage planes are (<span><math><mrow><mover><mrow><mn>1</mn></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span> 12) and (<span><math><mrow><mover><mrow><mn>1</mn></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mn>1</mn></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math></span> 2). Based on the nanobelts, multi-MOSFET device process integration is carried out, and a 150 × 150 μm<sup>2</sup> source/drain electrode placement is achieved on a 165 μm-wide nanobelt. The dark drain current is extremely low of about 10<sup>-13</sup> A. Under the 254 nm solar-blind UV light, MOSFET exhibits the excellent gate control characteristics. This study highlights the significant application potential of the distinctive crystal morphology of β-Ga<sub>2</sub>O<sub>3</sub> nanobelts in future microelectronics.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"680 ","pages":"Article 128505"},"PeriodicalIF":2.0,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076446","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 : 2026-01-23DOI: 10.1016/j.jcrysgro.2026.128504
Afsaneh Kashizadeh , Rabin Basnet , Khoa Nguyen , Stephane Armand , Christian Samundsett , Wei Han , Yichun Wang , AnYao Liu , Daniel Macdonald
Recharged Czochralski (RCz) silicon is now the dominant substrate for industrial photovoltaics, yet research on radial dopant uniformity remains limited. In this study, we apply high-resolution steady-state photoluminescence (PL) imaging of the doping concentration, calibrated using eddy-current resistivity measurements, to characterize radial and axial dopant distributions in RCz-grown silicon wafers doped with antimony (Sb), phosphorus (P), and gallium (Ga). Despite their markedly different segregation coefficients, all three dopants exhibit highly uniform radial concentration profiles, with only weak (<10%) reductions in dopant concentration toward the wafer edges. These trends are consistent with the suppression of radial concentration gradients by crystal-crucible counter-rotation in the RCz process. Localized variations observed in the central ∼30 mm region are attributed to dopant redistribution driven by buoyancy- and Marangoni-driven melt convection. Axially along the length of the ingot, the wafers exhibit dopant distributions that are consistent with the combined effects of dopant segregation and evaporation: Sb-doped wafers show minimal doping variation along the ingot, whereas P- and Ga-doped wafers exhibit increasing doping concentrations toward the ingot tail. Calibrated PL measurements also reveal changes in apparent doping concentration arising from oxygen-related thermal donor (TD) formation and annihilation in Sb-doped samples after thermal treatments. These results demonstrate that RCz growth yields wafers with excellent radial dopant uniformity for the n- and p-type dopants studied here.
{"title":"Photoluminescence-based dopant imaging of Ga-, P- and Sb-doped Czochralski-grown silicon wafers for solar cells","authors":"Afsaneh Kashizadeh , Rabin Basnet , Khoa Nguyen , Stephane Armand , Christian Samundsett , Wei Han , Yichun Wang , AnYao Liu , Daniel Macdonald","doi":"10.1016/j.jcrysgro.2026.128504","DOIUrl":"10.1016/j.jcrysgro.2026.128504","url":null,"abstract":"<div><div>Recharged Czochralski (RCz) silicon is now the dominant substrate for industrial photovoltaics, yet research on radial dopant uniformity remains limited. In this study, we apply high-resolution steady-state photoluminescence (PL) imaging of the doping concentration, calibrated using eddy-current resistivity measurements, to characterize radial and axial dopant distributions in RCz-grown silicon wafers doped with antimony (Sb), phosphorus (P), and gallium (Ga). Despite their markedly different segregation coefficients, all three dopants exhibit highly uniform radial concentration profiles, with only weak (<10%) reductions in dopant concentration toward the wafer edges. These trends are consistent with the suppression of radial concentration gradients by crystal-crucible counter-rotation in the RCz process. Localized variations observed in the central ∼30 mm region are attributed to dopant redistribution driven by buoyancy- and Marangoni-driven melt convection. Axially along the length of the ingot, the wafers exhibit dopant distributions that are consistent with the combined effects of dopant segregation and evaporation: Sb-doped wafers show minimal doping variation along the ingot, whereas P- and Ga-doped wafers exhibit increasing doping concentrations toward the ingot tail. Calibrated PL measurements also reveal changes in apparent doping concentration arising from oxygen-related thermal donor (TD) formation and annihilation in Sb-doped samples after thermal treatments. These results demonstrate that RCz growth yields wafers with excellent radial dopant uniformity for the n- and p-type dopants studied here.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"680 ","pages":"Article 128504"},"PeriodicalIF":2.0,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076448","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}
N-polar aluminum nitride (AlN) is an ultra-wide bandgap semiconductor with significant potential not only in optical devices but also in high-power, high-frequency, and high-temperature electronic applications. However, the epitaxial growth of device-grade N-polar AlN films has been hindered by challenges in controlling surface kinetics and polarity. In this study, we demonstrate the fabrication of high-quality N-polar AlN films on Si-face 4H-SiC substrates by combining sputter deposition with face-to-face annealing (FFA Sp), and employing a controlled polarity inversion technique. The resulting N-polar AlN films were crack-free and exhibited atomically smooth surfaces, with a root-mean-square (RMS) roughness of approximately 0.15 nm. The full width at half maximum (FWHM) values of the X-ray rocking curves for the (0002) and (10–12) diffraction peaks were measured to be 89 arcsec and 238 arcsec, respectively, corresponding to threading dislocation density (TDD) of approximately 6.5 × 108 cm−2. Cross-sectional TEM analysis confirmed similarly low TDD (∼1.5 × 108 cm−2). These results demonstrate an effective and scalable route for achieving high-quality N-polar AlN films on 4H-SiC substrates.
{"title":"Fabrication of N-polar AlN films on 4H-SiC substrates via polarity inversion technique","authors":"Yuning Wang , Tomohiro Tamano , Tomoya Higashi , Ryota Akaike , Hiroki Yasunaga , Hideto Miyake","doi":"10.1016/j.jcrysgro.2026.128503","DOIUrl":"10.1016/j.jcrysgro.2026.128503","url":null,"abstract":"<div><div>N-polar aluminum nitride (AlN) is an ultra-wide bandgap semiconductor with significant potential not only in optical devices but also in high-power, high-frequency, and high-temperature electronic applications. However, the epitaxial growth of device-grade N-polar AlN films has been hindered by challenges in controlling surface kinetics and polarity. In this study, we demonstrate the fabrication of high-quality N-polar AlN films on Si-face 4H-SiC substrates by combining sputter deposition with face-to-face annealing (FFA Sp), and employing a controlled polarity inversion technique. The resulting N-polar AlN films were crack-free and exhibited atomically smooth surfaces, with a root-mean-square (RMS) roughness of approximately 0.15 nm. The full width at half maximum (FWHM) values of the X-ray rocking curves for the (0002) and (10–12) diffraction peaks were measured to be 89 arcsec and 238 arcsec, respectively, corresponding to threading dislocation density (TDD) of approximately 6.5 × 10<sup>8</sup> cm<sup>−2</sup>. Cross-sectional TEM analysis confirmed similarly low TDD (∼1.5 × 10<sup>8</sup> cm<sup>−2</sup>). These results demonstrate an effective and scalable route for achieving high-quality N-polar AlN films on 4H-SiC substrates.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"680 ","pages":"Article 128503"},"PeriodicalIF":2.0,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037031","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 : 2026-01-17DOI: 10.1016/j.jcrysgro.2026.128501
Yanbing Zhu , Yubai Zhang , Jiani Wang , Songyan Jia , Yali Ma , Gang Li , Xue Li , Qiang Zheng
Brucite, an underutilized magnesium-rich mineral, exhibits untapped potential for magnesium hydroxide (Mg(OH)2) production, yet its utility in fabrication non-typical crystal morphologies remains underexplored. This study presents a novel strategy for the controlled synthesis of Mg(OH)2 with a unique triangular pyramidal morphology via a calcination-hydration process using brucite, coupled with a systematic elucidation of its morphological evolution and hydration kinetics. The results reveal that the triangular pyramidal structure is attributed to the selective adsorption of H2SiO42− on specific crystal planes during initial hydration. As hydration proceeds, a dissolution–recrystallization mechanism governs the morphological evolution from triangular pyramids to hexagonal plates, with edge and vertex dissolution of initial nuclei underpinning the formation of thermodynamically stable hexagonal lamellae. Kinetic analysis, employing the Avrami model and Arrhenius equation, reveals that the hydration process is governed by synergistic nucleation and growth behavior, with finer brucite particles exhibiting a lower activation energy (26.22 kJ·mol−1) and faster reaction rates compared to coarser particles (46.20 kJ·mol−1). This work not only elucidates the Si-mediated morphological evolution mechanism of Mg(OH)2 from brucite but also provides critical kinetic insights for optimizing the synthesis of special crystal morphologies, providing a viable pathway to valorize low-grade brucite resources for advanced functional material applications.
{"title":"Controlled synthesis of Mg(OH)2 with tailored crystal morphologies from brucite via hydration: Morphological evolution mechanism and hydration kinetics","authors":"Yanbing Zhu , Yubai Zhang , Jiani Wang , Songyan Jia , Yali Ma , Gang Li , Xue Li , Qiang Zheng","doi":"10.1016/j.jcrysgro.2026.128501","DOIUrl":"10.1016/j.jcrysgro.2026.128501","url":null,"abstract":"<div><div>Brucite, an underutilized magnesium-rich mineral, exhibits untapped potential for magnesium hydroxide (Mg(OH)<sub>2</sub>) production, yet its utility in fabrication non-typical crystal morphologies remains underexplored. This study presents a novel strategy for the controlled synthesis of Mg(OH)<sub>2</sub> with a unique triangular pyramidal morphology via a calcination-hydration process using brucite, coupled with a systematic elucidation of its morphological evolution and hydration kinetics. The results reveal that the triangular pyramidal structure is attributed to the selective adsorption of H<sub>2</sub>SiO<sub>4</sub><sup>2−</sup> on specific crystal planes during initial hydration. As hydration proceeds, a dissolution–recrystallization mechanism governs the morphological evolution from triangular pyramids to hexagonal plates, with edge and vertex dissolution of initial nuclei underpinning the formation of thermodynamically stable hexagonal lamellae. Kinetic analysis, employing the Avrami model and Arrhenius equation, reveals that the hydration process is governed by synergistic nucleation and growth behavior, with finer brucite particles exhibiting a lower activation energy (26.22 kJ·mol<sup>−1</sup>) and faster reaction rates compared to coarser particles (46.20 kJ·mol<sup>−1</sup>). This work not only elucidates the Si-mediated morphological evolution mechanism of Mg(OH)<sub>2</sub> from brucite but also provides critical kinetic insights for optimizing the synthesis of special crystal morphologies, providing a viable pathway to valorize low-grade brucite resources for advanced functional material applications.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128501"},"PeriodicalIF":2.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035715","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 : 2026-01-10DOI: 10.1016/j.jcrysgro.2026.128491
Zhongjun Cao , Jianyu Bai , Guokai Hao , Yang Li , Guodong Lei , Lisong Zhang , Mingxia Xu , Hongkai Ren , Baoan Liu , Xun Sun
A high-efficiency gradient-refractive-index deuterated potassium dihydrogen phosphate (DKDP) crystal, prepared via a confined growth method based on the point-seed rapid growth technique, demonstrates optimized broadband third-harmonic generation performance. By restricting crystal growth within a cylindrical glass tube, this work systematically reveals the critical effects of confinement on mass transport and convective dynamics during crystal growth. Numerical simulations employing the finite volume method with the SST k-ω turbulence model are utilized to elucidate the regulatory mechanisms of rotation speed on both the magnitude and uniformity of surface supersaturation. Following preliminary screening of rotation parameters, orthogonal experimental design enabled the multivariate optimization of cylindrical glass tube dimensions (diameter/height) and rotation speed within predefined boundaries. Through comprehensive analysis of convective transport characteristics and surface supersaturation distributions under diverse parameter combinations, a theoretical framework integrating growth vessel design and kinetic parameter matching is established. This work provides a usable method for the controllable growth of functional crystals.
{"title":"Numerical simulation of mass transfer and hydrodynamics in confined growth of KDP crystals","authors":"Zhongjun Cao , Jianyu Bai , Guokai Hao , Yang Li , Guodong Lei , Lisong Zhang , Mingxia Xu , Hongkai Ren , Baoan Liu , Xun Sun","doi":"10.1016/j.jcrysgro.2026.128491","DOIUrl":"10.1016/j.jcrysgro.2026.128491","url":null,"abstract":"<div><div>A high-efficiency gradient-refractive-index deuterated potassium dihydrogen phosphate (DKDP) crystal, prepared via a confined growth method based on the point-seed rapid growth technique, demonstrates optimized broadband third-harmonic generation performance. By restricting crystal growth within a cylindrical glass tube, this work systematically reveals the critical effects of confinement on mass transport and convective dynamics during crystal growth. Numerical simulations employing the finite volume method with the SST k-ω turbulence model are utilized to elucidate the regulatory mechanisms of rotation speed on both the magnitude and uniformity of surface supersaturation. Following preliminary screening of rotation parameters, orthogonal experimental design enabled the multivariate optimization of cylindrical glass tube dimensions (diameter/height) and rotation speed within predefined boundaries. Through comprehensive analysis of convective transport characteristics and surface supersaturation distributions under diverse parameter combinations, a theoretical framework integrating growth vessel design and kinetic parameter matching is established. This work provides a usable method for the controllable growth of functional crystals.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128491"},"PeriodicalIF":2.0,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975536","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 : 2026-01-10DOI: 10.1016/j.jcrysgro.2026.128490
Lorenz Taucher , Zaher Ramadan , René Hammer , Stefan Defregger , Peter Auer , Lorenz Romaner
The physical vapor transport (PVT) method is the most commonly applied growth technique for bulk SiC single crystals. Nowadays, the increasing demand of SiC substrates inevitably requires the adaption of PVT reactors to larger boule diameters. Since the boule quality and the single-crystal yield are primarily dependent on the thermal field inside the growth chamber and its stability, the control and optimization of the thermal conditions are the most crucial aspects to address. In this respect, the temperature difference along the seed, in the source and between source and seed, in addition to the growth temperature, are of particular interest. Due to the quasi-closed nature of the PVT system, in-situ measurements are hardly feasible, making numerical simulations the primary tool for analyzing the thermal field. But, since the high computational demand of these simulations restricts the number of cases that can be practically evaluated, numerical in-depth investigations are constrained. Attributed to this, the present study demonstrates an efficient way for constrained multi-objective optimization of the thermal field of PVT simulations by leveraging the correlation within the data through singular value decomposition (SVD). A 6-inch inductively heated PVT reactor is taken as a representative example and is optimized by combining machine learning models with numerical simulation data and optimization algorithms. In general, this approach enables the identification of optimal process parameters and reactor configurations, while revealing inherent tradeoffs between objectives and operational limitations, regardless of the PVT furnace operation principle (resistive or inductive) or seed crystal diameter (6-inch, 8-inch, etc.). Furthermore, it allows for an in-depth analysis of optimal settings, parameter sensitivities, interdependencies and solution robustness.
{"title":"Efficient thermal field optimization of PVT simulations for SiC single crystal growth","authors":"Lorenz Taucher , Zaher Ramadan , René Hammer , Stefan Defregger , Peter Auer , Lorenz Romaner","doi":"10.1016/j.jcrysgro.2026.128490","DOIUrl":"10.1016/j.jcrysgro.2026.128490","url":null,"abstract":"<div><div>The physical vapor transport (PVT) method is the most commonly applied growth technique for bulk SiC single crystals. Nowadays, the increasing demand of SiC substrates inevitably requires the adaption of PVT reactors to larger boule diameters. Since the boule quality and the single-crystal yield are primarily dependent on the thermal field inside the growth chamber and its stability, the control and optimization of the thermal conditions are the most crucial aspects to address. In this respect, the temperature difference along the seed, in the source and between source and seed, in addition to the growth temperature, are of particular interest. Due to the quasi-closed nature of the PVT system, <em>in-situ</em> measurements are hardly feasible, making numerical simulations the primary tool for analyzing the thermal field. But, since the high computational demand of these simulations restricts the number of cases that can be practically evaluated, numerical in-depth investigations are constrained. Attributed to this, the present study demonstrates an efficient way for constrained multi-objective optimization of the thermal field of PVT simulations by leveraging the correlation within the data through singular value decomposition (SVD). A 6-inch inductively heated PVT reactor is taken as a representative example and is optimized by combining machine learning models with numerical simulation data and optimization algorithms. In general, this approach enables the identification of optimal process parameters and reactor configurations, while revealing inherent tradeoffs between objectives and operational limitations, regardless of the PVT furnace operation principle (resistive or inductive) or seed crystal diameter (6-inch, 8-inch, etc.). Furthermore, it allows for an in-depth analysis of optimal settings, parameter sensitivities, interdependencies and solution robustness.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128490"},"PeriodicalIF":2.0,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975538","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 : 2026-01-09DOI: 10.1016/j.jcrysgro.2026.128492
Junling Ding , Haowen Yu , Zaoyang Li , Qiping Chen , Pengfei Wang , Lijun Liu
The distribution of phosphorus dopant in silicon has an important influence on the resistivity of silicon crystals. A two-dimensional transient global model is established in this paper to investigate the transport of phosphorus dopant during the iso-diameter growth of 200 mm Czochralski monocrystalline silicon. We focused on the dynamic consumption process of phosphorus dopant in the silicon melt during crystal growth, and analyzed the effects of segregation and evaporation behavior, as well as the turbulent viscosity on the transport of phosphorus dopant. The results reveal that the concentration of phosphorus dopant at crystal-melt interface exhibits a trend in which the concentration is elevated at the center compared to the edge. Furthermore, the phosphorus dopant concentration in the melt progressively increases with crystal growth, resulting in a higher content in the tail of monocrystalline silicon compared to the head. By comparing with the experimental data, it is confirmed that when calculating the transport of phosphorus dopant in the melt, the melt turbulent viscosity and the evaporation behavior of phosphorus needs to be considered. At the same time, we also determined the evaporation coefficient for accurately calculating phosphorus dopant distribution.
{"title":"Study on the transport of phosphorus dopant during the n-type monocrystalline silicon growth by Czochralski technique","authors":"Junling Ding , Haowen Yu , Zaoyang Li , Qiping Chen , Pengfei Wang , Lijun Liu","doi":"10.1016/j.jcrysgro.2026.128492","DOIUrl":"10.1016/j.jcrysgro.2026.128492","url":null,"abstract":"<div><div>The distribution of phosphorus dopant in silicon has an important influence on the resistivity of silicon crystals. A two-dimensional transient global model is established in this paper to investigate the transport of phosphorus dopant during the <em>iso</em>-diameter growth of 200 mm Czochralski monocrystalline silicon. We focused on the dynamic consumption process of phosphorus dopant in the silicon melt during crystal growth, and analyzed the effects of segregation and evaporation behavior, as well as the turbulent viscosity on the transport of phosphorus dopant. The results reveal that the concentration of phosphorus dopant at crystal-melt interface exhibits a trend in which the concentration is elevated at the center compared to the edge. Furthermore, the phosphorus dopant concentration in the melt progressively increases with crystal growth, resulting in a higher content in the tail of monocrystalline silicon compared to the head. By comparing with the experimental data, it is confirmed that when calculating the transport of phosphorus dopant in the melt, the melt turbulent viscosity and the evaporation behavior of phosphorus needs to be considered. At the same time, we also determined the evaporation coefficient for accurately calculating phosphorus dopant distribution.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128492"},"PeriodicalIF":2.0,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975537","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 : 2026-01-09DOI: 10.1016/j.jcrysgro.2026.128493
Elisa García-Tabarés , Víctor Orejuela , Ignacio Rey-Stolle , Verónica Braza , Daniel F. de los Reyes , Paula Mouriño , Raquel Resta , Víctor J. Gómez , Pere Roca i Cabarrocas , Iván García
The integration of III-V semiconductors on silicon through Ge|Si virtual substrates has shown significant potential. Conventional methods typically employ relatively thick Ge layers (several microns) to produce surfaces with low defect densities, though these layers introduce constraints—particularly the risk of cracking—due to the differing thermal expansion coefficients between Si, Ge, and subsequent III-V materials. A novel approach was developed to alleviate thermal strain by drastically reducing the Ge layer thickness (<200 nm) and deposition temperature (<250 °C) using PECVD. Remarkably low threading dislocation densities (∼106 cm−2) were reported for these substrates, making them attractive for III-V growth. However, the integration of III-V materials on these substrates has yielded devices with subpar performance, especially in photovoltaic applications. The origin of these defects may lie in the Ge|Si substrates or arise during subsequent III-V growth via MOVPE. This study investigates the reasons why ultrathin Ge|Si virtual substrates have yet to produce high-performance solar cells. To this end, a comprehensive set of Ga(In)As/Ge|Si structures was fabricated and analyzed in depth using SEM, TEM, and AFM. Results reveal that defects initiate at the Ge|Si interface and propagate throughout the III-V layers, with Ge layer thickness in the range from 20 to 120 nm having minimal impact on defect formation. Furthermore, the MOVPE process for III-V growth was found to have a limited effect on the structural integrity of the substrates. Our findings suggest that, while ultrathin Ge|Si virtual substrates may not currently be suitable for high-efficiency III-V solar cells, they could still be viable for other optoelectronic devices less dependent on minority carrier properties.
{"title":"Characterization of III-V layers grown on Ge|Si virtual substrates fabricated by LT-PECVD for photovoltaic devices","authors":"Elisa García-Tabarés , Víctor Orejuela , Ignacio Rey-Stolle , Verónica Braza , Daniel F. de los Reyes , Paula Mouriño , Raquel Resta , Víctor J. Gómez , Pere Roca i Cabarrocas , Iván García","doi":"10.1016/j.jcrysgro.2026.128493","DOIUrl":"10.1016/j.jcrysgro.2026.128493","url":null,"abstract":"<div><div>The integration of III-V semiconductors on silicon through Ge|Si virtual substrates has shown significant potential. Conventional methods typically employ relatively thick Ge layers (several microns) to produce surfaces with low defect densities, though these layers introduce constraints—particularly the risk of cracking—due to the differing thermal expansion coefficients between Si, Ge, and subsequent III-V materials. A novel approach was developed to alleviate thermal strain by drastically reducing the Ge layer thickness (<200 <!--> <!-->nm) and deposition temperature (<250 °C) using PECVD. Remarkably low threading dislocation densities (∼10<sup>6</sup> <!-->cm<sup>−2</sup>) were reported for these substrates, making them attractive for III-V growth. However, the integration of III-V materials on these substrates has yielded devices with subpar performance, especially in photovoltaic applications. The origin of these defects may lie in the Ge|Si substrates or arise during subsequent III-V growth via MOVPE. This study investigates the reasons why ultrathin Ge|Si virtual substrates have yet to produce high-performance solar cells. To this end, a comprehensive set of Ga(In)As/Ge|Si structures was fabricated and analyzed in depth using SEM, TEM, and AFM. Results reveal that defects initiate at the Ge|Si interface and propagate throughout the III-V layers, with Ge layer thickness in the range from 20 to 120 nm having minimal impact on defect formation. Furthermore, the MOVPE process for III-V growth was found to have a limited effect on the structural integrity of the substrates. Our findings suggest that, while ultrathin Ge|Si virtual substrates may not currently be suitable for high-efficiency III-V solar cells, they could still be viable for other optoelectronic devices less dependent on minority carrier properties.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"680 ","pages":"Article 128493"},"PeriodicalIF":2.0,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076447","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 : 2026-01-07DOI: 10.1016/j.jcrysgro.2026.128488
XianRong Huang, Lahsen Assoufid
The beamline 1-BM of the Advanced Photon Source (APS), a bending-magnet beamline with an effective X-ray beam size of ∼ mm2, has relatively comprehensive synchrotron topography and rocking curve imaging capabilities for characterization of crystals (particularly wide-bandgap semiconductors SiC, AlN, GaN, Ga2O3 etc). It is equipped with a white-beam topography stage for imaging large wafers up to 8 in.. It also has a double-crystal setup, of which the second stage can be used for monochromatic-beam topography. The first stage has different beam conditioners in the grazing-incidence geometry that can expand the vertical beam size from 4 to ∼100 mm for double-crystal rocking curve imaging when it is combined with the second stage. Recently APS has been upgraded to a modern 4th-generation light source, and 1-BM has been recommissioned to its normal operation for general users with better performance. The upgraded APS leads to new features at 1-BM. The much smaller source size and higher X-ray coherence significantly improve the image resolution and contrast. The higher flux and brightness of the new source reduce exposure time, which mitigates the mechanical drifting and vibration issues. Here the main capabilities and status of 1-BM together with these new features are introduced.
{"title":"Status and new features of the topography beamline 1-BM after the Advanced Photon Source upgrade","authors":"XianRong Huang, Lahsen Assoufid","doi":"10.1016/j.jcrysgro.2026.128488","DOIUrl":"10.1016/j.jcrysgro.2026.128488","url":null,"abstract":"<div><div>The beamline 1-BM of the Advanced Photon Source (APS), a bending-magnet beamline with an effective X-ray beam size of ∼<span><math><mrow><mn>100</mn><mo>×</mo><mn>4</mn></mrow></math></span> mm<sup>2</sup>, has relatively comprehensive synchrotron topography and rocking curve imaging capabilities for characterization of crystals (particularly wide-bandgap semiconductors SiC, AlN, GaN, Ga<sub>2</sub>O<sub>3</sub> etc). It is equipped with a white-beam topography stage for imaging large wafers up to 8 in.. It also has a double-crystal setup, of which the second stage can be used for monochromatic-beam topography. The first stage has different beam conditioners in the grazing-incidence geometry that can expand the vertical beam size from 4 to ∼100 mm for double-crystal rocking curve imaging when it is combined with the second stage. Recently APS has been upgraded to a modern 4th-generation light source, and 1-BM has been recommissioned to its normal operation for general users with better performance. The upgraded APS leads to new features at 1-BM. The much smaller source size and higher X-ray coherence significantly improve the image resolution and contrast. The higher flux and brightness of the new source reduce exposure time, which mitigates the mechanical drifting and vibration issues. Here the main capabilities and status of 1-BM together with these new features are introduced.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128488"},"PeriodicalIF":2.0,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975534","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 : 2026-01-06DOI: 10.1016/j.jcrysgro.2026.128487
Wei Hu , Guang Wen , Rongcheng Yao , Shuixiu Lin , Lingyu Wan , Shengnan Zhang , Yinming Wang , Manika Tun Nafisa , Zhe Chuan Feng , Benjamin Klein , Ian T. Ferguson
Systematic investigations of microstructure, the optical properties, band gap and variable temperature behaviors are conducted comparatively for Si/Mg-doped β-Ga2O3 crystals by edge-defined film-fed growth (EFG). The X-ray diffraction results revealed that compared with unintentionally doped β-Ga2O3 single crystals, Si doping led to a decrease in the interplanar spacing of the (400), (600), and (800) crystal planes in β-Ga2O3 single crystals, while Mg doping resulted in an increase in their interplanar spacing. Through a comprehensive analysis of the dataset of Room-temperature photoluminescence (PL), we identified that the defect-related luminescence of the two samples exhibited significantly changed. For the Si-doped sample, the PL blue emission was strong while the red emission was weak; in contrast, the Mg-doped sample showed the opposite trend, with strong red emission and weak blue emission, accompanied by multiple narrow-band red luminescence peaks. Variable-temperature photoluminescence (PL) results showed that the luminescence peak position of Si-doped β-Ga2O3 first redshifted and then blue shifted with increasing temperature, while the luminescence peak position and intensity of the Mg-doped sample exhibited a monotonous decreasing trend. Further analysis revealed that Si doping reduced the band gap, with the Fermi level moving closer to the conduction band bottom; in contrast, Mg doping increased the band gap, causing the Fermi level to shift toward the middle of the band gap. Under the variable-temperature condition from 10 K to 300 K, the temperature-dependent variation of the band gap conforms to the Varshni formula.
{"title":"Si (Mg) doping in β-Ga2O3 crystals by edge-defined film-fed growth: A comparative analysis of microstructure, bandgap, and temperature-dependent properties","authors":"Wei Hu , Guang Wen , Rongcheng Yao , Shuixiu Lin , Lingyu Wan , Shengnan Zhang , Yinming Wang , Manika Tun Nafisa , Zhe Chuan Feng , Benjamin Klein , Ian T. Ferguson","doi":"10.1016/j.jcrysgro.2026.128487","DOIUrl":"10.1016/j.jcrysgro.2026.128487","url":null,"abstract":"<div><div>Systematic investigations of microstructure, the optical properties, band gap and variable temperature behaviors are conducted comparatively for Si/Mg-doped β-Ga<sub>2</sub>O<sub>3</sub> crystals by edge-defined film-fed growth (EFG). The X-ray diffraction results revealed that compared with unintentionally doped β-Ga<sub>2</sub>O<sub>3</sub> single crystals, Si doping led to a decrease in the interplanar spacing of the (400), (600), and (800) crystal planes in β-Ga<sub>2</sub>O<sub>3</sub> single crystals, while Mg doping resulted in an increase in their interplanar spacing. Through a comprehensive analysis of the dataset of Room-temperature photoluminescence (PL), we identified that the defect-related luminescence of the two samples exhibited significantly changed. For the Si-doped sample, the PL blue emission was strong while the red emission was weak; in contrast, the Mg-doped sample showed the opposite trend, with strong red emission and weak blue emission, accompanied by multiple narrow-band red luminescence peaks. Variable-temperature photoluminescence (PL) results showed that the luminescence peak position of Si-doped β-Ga<sub>2</sub>O<sub>3</sub> first redshifted and then blue shifted with increasing temperature, while the luminescence peak position and intensity of the Mg-doped sample exhibited a monotonous decreasing trend. Further analysis revealed that Si doping reduced the band gap, with the Fermi level moving closer to the conduction band bottom; in contrast, Mg doping increased the band gap, causing the Fermi level to shift toward the middle of the band gap. Under the variable-temperature condition from 10 K to 300 K, the temperature-dependent variation of the band gap conforms to the Varshni formula.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"679 ","pages":"Article 128487"},"PeriodicalIF":2.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941266","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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