Progress in Crystal Growth and Characterization of Materials最新文献

{"title":"Bragg diffraction imaging characterization of crystal defects in GaN (0001) substrates: Comparison of the growth method and the seed approach","authors":"Lutz Kirste ,&nbsp;Thu Nhi Tran-Caliste ,&nbsp;Tomasz Sochacki ,&nbsp;Jan L. Weyher ,&nbsp;Patrik Straňák ,&nbsp;Robert Kucharski ,&nbsp;Karolina Grabianska ,&nbsp;José Baruchel ,&nbsp;Michal Bockowski","doi":"10.1016/j.pcrysgrow.2025.100668","DOIUrl":"10.1016/j.pcrysgrow.2025.100668","url":null,"abstract":"<div><div>We investigate the defect structure of gallium nitride (GaN) substrates grown by hydride vapor phase epitaxy (HVPE) and ammonothermal method, with emphasis on the seeding approach (“foreign seed” or “native seed”). X-ray Bragg diffraction imaging techniques (laboratory X-ray Lang topography (L-XRT) and synchrotron monochromatic rocking curve imaging (RCI)) were used to study the defects of the GaN substrates. The efficiency of the in-process L-XRT method, whereas being strongly dependent on the structural perfection of the crystals, is important because it provides a good overview of the defect structure for entire substrates. But it remains qualitative, or semi-quantitative. RCI, on the other hand, allows obtaining complete quantitative information about lattice misorientation and distortion with sub-µm resolution. The contrast of the diffraction images of defects such as grain boundaries, dislocations, dislocation bundles, planar defects and others, is discussed, with emphasis on the influence of threading dislocation density on the contrast of the Bragg diffraction imaging. We complemented the diffraction studies with defect selective etching analyses and, to determine the level of impurities in the GaN substrates, by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The main finding of this study is that a native seed approach is essential for crystallizing GaN with high structural perfection and low threading dislocation density. This is true whether the GaN crystals are grown by HVPE or ammonothermal methods. A potential route to low-defect, low-impurity GaN substrates is outlined as a fundamental element for realizing GaN-based devices with high performance, life-time, and reliability.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 3","pages":"Article 100668"},"PeriodicalIF":4.5,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical pressure due to impurities in trigonal compounds EuT2Pn2 (T= Cd, Zn; Pn= P, As, Sb)","authors":"Kristin Kliemt","doi":"10.1016/j.pcrysgrow.2025.100667","DOIUrl":"10.1016/j.pcrysgrow.2025.100667","url":null,"abstract":"<div><div>This work provides a review of crystal growth, crystal structure, compositional details, magnetism, thermodynamic, and transport behavior in the family of the trigonal intermetallic systems Eu<span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>P</mi><msub><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> (<span><math><mrow><mi>T</mi><mo>=</mo></mrow></math></span> Cd, Zn; <span><math><mrow><mi>P</mi><mi>n</mi><mo>=</mo></mrow></math></span> P, As, Sb; space group <span><math><mrow><mi>P</mi><mover><mrow><mn>3</mn></mrow><mo>¯</mo></mover><mi>m</mi><mn>1</mn></mrow></math></span>, No. 164). The physical properties observed in these materials, and how these change depending on the growth conditions are discussed. In particular, the case of EuCd<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is considered where data from many sources are available. The possible small contamination of the material during crystal growth experiments is hard to verify as it is often below the detection limit of the standard characterization techniques. It turns out that samples from different sources exhibit variations in the lattice parameters exceeding the experimental errors. The review of these parameters reveals that they are very similar for antiferromagnetic samples grown from Sn flux in Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> crucibles, while there is a wider spread for samples grown from salt flux grown in SiO₂ ampules, which are mostly ferromagnetic. The influence of the different experimental setups with regard to possible impurities in the samples is discussed.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100667"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The growth of titanium doped sapphire for laser application","authors":"Lingling Xuan,&nbsp;Thierry Duffar","doi":"10.1016/j.pcrysgrow.2025.100666","DOIUrl":"10.1016/j.pcrysgrow.2025.100666","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The main application of Ti doped sapphire (Ti:sapphire) lies in the field of lasers, thanks to its outstanding production of ultra-short pulses due to the presence of doping Ti&lt;sup&gt;3+&lt;/sup&gt; ions. The absorption and emission mechanisms of this crystal are intricate, necessitating consideration of point defects existing in the grown crystal. A plethora of liquid-phase growth methods yield crystals of diverse sizes and quality. This paper gives a comprehensive review of the literature on managing dopants during the growth of Ti doped bulk sapphire crystals.&lt;/div&gt;&lt;div&gt;Substantial research has indicated that the presence of detrimental Ti&lt;sup&gt;4+&lt;/sup&gt; ions diminishes the crystal laser efficiency due to their residual absorption. Although annealing under reducing atmosphere is an efficient way to increase the Ti&lt;sup&gt;3+&lt;/sup&gt;/Ti&lt;sup&gt;4+&lt;/sup&gt; ratio, this process becomes increasingly time-consuming as the demand for larger optical components increases. Consequently, it would be more practical and convenient to control this ratio directly during the growth processes. However, the conversion mechanisms between the two Ti ions valences during crystal growth and annealing remain largely unexplored.&lt;/div&gt;&lt;div&gt;A study of the thermodynamics of the Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/TiO&lt;sub&gt;2&lt;/sub&gt; and Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/Ti&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; solid and liquid solutions as a function of the partial pressure (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) and oxygen activity is crucial for understanding these mechanisms. This paper presents corrected, reliable phase diagrams that enable quantitative prediction of the effect of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; on the melt concentrations of the two ions. Consequently, a novel value of the absorption coefficient constant, pertinent to Ti&lt;sup&gt;4+&lt;/sup&gt; concentration measurement, is proposed. Equilibrium with the solid solution yields segregation coefficients that appear distinct for the two ions. Given their influence on oxygen activity during growth, the effect of surrounding furnace parts, such as graphite casing or Mo crucible, is also important.&lt;/div&gt;&lt;div&gt;Understanding the behavior of Ti&lt;sup&gt;3+&lt;/sup&gt;and Ti&lt;sup&gt;4+&lt;/sup&gt; ions in the grown crystal as a function of pulling time and considering the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; levels in the furnace atmosphere, requires the knowledge of solid-state electrochemistry, including the charge carriers and the Al and O vacancies. This foundation allows the development of a physico-chemical model illustrating the evolution of ion valence during growth. Analysis of experimental results from existing literature gives the necessary diffusion coefficients and reaction rate constants. Investigating crystal-atmosphere interaction provides the required boundary condition for solving the problem. The findings exhibit qualitative ag","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100666"},"PeriodicalIF":4.5,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of micro-Raman technique in material characterization of GaN wide bandgap semiconductor: Review","authors":"P. Atheek ,&nbsp;P. Puviarasu ,&nbsp;S. Munawar Basha ,&nbsp;G. Balaji","doi":"10.1016/j.pcrysgrow.2025.100665","DOIUrl":"10.1016/j.pcrysgrow.2025.100665","url":null,"abstract":"<div><div>Gallium Nitride (GaN) materials have unique electronic, optical, and mechanical properties that make them useful for various applications. However, these materials have complex structures and behavior, making it challenging to characterize them. Micro-Raman spectroscopy (MRS) is an appreciatively effective and adaptable method for analyzing the different properties of GaN materials, such as stress, strain, carrier concentration, and phonon lifetime. This review article provides an overview of the principles of MRS and its applications in GaN material characterization. The behavior of <span><math><msubsup><mi>E</mi><mn>2</mn><mi>H</mi></msubsup></math></span> vibration modes of GaN material depends on the defects in the epilayer which alters the materials physical properties, such as stress and strain. The A₁(LO) vibration mode of longitudinal optical phonons provides information on electrical properties, such as carrier concentration and phonon lifetime. This review explains the MRS use in quantifying the physical and electrical properties of GaN materials over other characterization.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 2","pages":"Article 100665"},"PeriodicalIF":4.5,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology features of β-Ga2O3 bulk crystals by EFG and CZ methods: A review","authors":"Mujie Xu ,&nbsp;Zining Wang ,&nbsp;Rui Wang ,&nbsp;Zhihong Yu ,&nbsp;Zhenhao Sun ,&nbsp;Bo Fu ,&nbsp;Yujun Shi","doi":"10.1016/j.pcrysgrow.2024.100658","DOIUrl":"10.1016/j.pcrysgrow.2024.100658","url":null,"abstract":"<div><div>High-quality crystals commonly exhibit regular morphology features and symmetries related to their crystal structures. The recognition of morphology features, especially on the shoulder morphology, will provide crucial guidance for the crystal growth and quality control. Here, the morphology features of <em>β</em>-Ga₂O₃ bulk crystals were discussed from three aspects of growth technology, orientation of seed crystal as well as pulling and rotation rates. Combined with the theoretical morphology of <em>β</em>-Ga₂O₃ crystal, the morphology features of <em>β</em>-Ga₂O₃ bulk crystals under different growth conditions were illuminated and summarized. The hexagonal seed crystal was also demonstrated, and more suitable for the growth of <em>β</em>-Ga₂O₃ bulk crystals with different principle surfaces by EFG method. The first review in the morphology features will become an important reference for future research on the growth of <em>β</em>-Ga₂O₃ bulk crystals.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 1","pages":"Article 100658"},"PeriodicalIF":4.5,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metastable zone width of different solute-solvent systems during cooling crystallization: Experimental observations and their interpretation","authors":"Keshra Sangwal,&nbsp;Wiesław Z. Polak","doi":"10.1016/j.pcrysgrow.2024.100657","DOIUrl":"10.1016/j.pcrysgrow.2024.100657","url":null,"abstract":"<div><div>Experimental observations of metastable zone width (MSZW) of various solute−solvent systems obtained by cooling crystallization at controlled rates <em>R</em>_L are reviewed and interpreted from the standpoint of deterministic theoretical models based on the classical three-dimensional (3D) nucleation theory containing two nucleation parameters: effective solid−solvent interfacial energy <em>γ</em>_eff and preexponential factor <em>A</em> for nucleation. After a brief introduction to the parameters <em>F</em> and <em>F</em>₁ of the models in terms of nucleation parameters of the classical nucleation theory and the effects of additives contained in the solution on the nucleation parameters <em>A</em> and <em>γ</em>_eff, typical experimental data of MSZW for selected solute−solvent systems are described and discussed according to the models to observe general trends of variations of <em>γ</em>_eff and <em>A</em> as functions of solution saturation temperature <em>T</em>₀ and concentration <em>c</em>_i of additives contained in the saturated solutions of different systems. Thereafter the observed general trends of variations of <em>γ</em>_eff and <em>A</em> as functions of solution saturation temperature <em>T</em>₀, solvent and concentration <em>c</em>_i of additives contained in the saturated solutions of different systems are discussed. The dimensions of 3D nuclei formed during MSZW of different systems and the limitations and applicability of deterministic models in crystallization processes are then presented and discussed. Finally, a summary of the contents of the review is given.</div></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"71 1","pages":"Article 100657"},"PeriodicalIF":4.5,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dr Narsingh Singh is retiring from the board","authors":"","doi":"10.1016/j.pcrysgrow.2024.100647","DOIUrl":"10.1016/j.pcrysgrow.2024.100647","url":null,"abstract":"","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"70 4","pages":"Article 100647"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel enhancing materials for biosensor design: The case studies of erbium-, gadolinium- and strontium-doped Ca10(PO4)6(OH)2 hydroxyapatite","authors":"Viviana Scognamiglio ,&nbsp;Valeria Nocerino ,&nbsp;Bruno Miranda ,&nbsp;Luca De Stefano ,&nbsp;Emanuela Tempesta ,&nbsp;Manuela Rossi ,&nbsp;Francesco Baldassarre ,&nbsp;Angela Altomare ,&nbsp;Francesco Capitelli","doi":"10.1016/j.pcrysgrow.2024.100637","DOIUrl":"10.1016/j.pcrysgrow.2024.100637","url":null,"abstract":"<div><p>Hydroxyapatite (HAp), ideal formula Ca₁₀(PO₄)₆(OH)₂, has unique physicochemical properties, including an excellent adsorption ability for functional biomolecules (e.g. nucleic acids, proteins) thanks to its specific large crystal surface. This property can be further improved with cationic and anionic replacements within the HAp framework. The adsorption of such biomolecules, indeed, can cause changes in the electric properties of the HAp surface in terms of resistivity and capacitance, generating the conditions for an improvement of the materials targeted for sensor applications. This work relates to the multiple routes for the synthesis of HAp materials, their electrochemical and structural investigations, and a short overview on the most well-known applications in sensor design. Moreover, with the aim of finding new promising HAp-based materials tailored for bioreceptor immobilization in biosensing, we underwent some doped-hydroxyapatite materials, specifically Sr-HAp, Gd-HAp, and Er-HAp, to a complete characterization. Electrochemical analyses, based on differential pulse voltammetry and cyclic voltammetry, evidenced improved analytical performances of HAp in terms of signal enhancement, repeatability, reproducibility, and reusability, in particular concerning the Er-HAp phase. A multi-methodological structural study, based on powder X-ray diffraction analysis, microscopy techniques (optical, electron, and fluorescence), energy dispersive X-ray spectroscopy (for chemical analyses), Fourier transform infrared spectroscopy, and absorption/fluorescence spectroscopies, showed the mechanism of doping replacement in HAp crystallographic sites, owing to the results of the Rietveld refinement from powder X-ray data, and a strong fluorescence for Sr-HAp.</p></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"70 4","pages":"Article 100637"},"PeriodicalIF":4.5,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrospray crystallization: A review on submicrometric and nanosized crystal synthesis","authors":"Angelo Oliveira Silva,&nbsp;Alessandro Rogério Paulazzi,&nbsp;Karina Luzia Andrade,&nbsp;Ricardo Antonio Francisco Machado,&nbsp;Cintia Marangoni,&nbsp;Dachamir Hotza","doi":"10.1016/j.pcrysgrow.2024.100636","DOIUrl":"https://doi.org/10.1016/j.pcrysgrow.2024.100636","url":null,"abstract":"<div><p>This review presents a comprehensive discussion of the electrospray crystallization process, which represents a combination of electrospraying and crystallization through solvent evaporation, offering an efficient and cost-effective approach for the synthesis of submicrometric and nanosized crystals. Electrospray crystallization has demonstrated a multitude of advantages, including the generation of smaller crystals, enhanced dispersion, and the creation of diverse product morphologies, such as planar and cubic tetragonal structures. These benefits surpass those of conventional electrospraying methods and traditional crystallization mechanisms. This review also provides a historical context of works and highlights the wide array of potential applications. It explores the mechanisms and fundamental concepts related to both electrospraying and crystallization processes. Moreover, it presents an experimental process development proposal, with the aim of charting a course for future applications of advanced crystals, including drug delivery, catalysis, and energy storage.</p></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"70 3","pages":"Article 100636"},"PeriodicalIF":4.5,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defect selective photoetching of GaN: Progress, applications and prospects","authors":"J.L. Weyher ,&nbsp;J.J. Kelly","doi":"10.1016/j.pcrysgrow.2024.100623","DOIUrl":"https://doi.org/10.1016/j.pcrysgrow.2024.100623","url":null,"abstract":"<div><p>Defect-selective etching methods are commonly used for a quick assessment of crystallographic and chemical inhomogeneities in various semiconductors, including nitrides. Because of the stability of GaN, \"extreme\" etchants such as molten bases and hot phosphoric/sulfuric acids are required for chemical etching. Photoetching provided an alternative and attractive path for room temperature etching of GaN. In this comprehensive review the introduction and subsequent modification of the photoetching method used for revealing defects and inhomogeneities in GaN are described in detail. The initial etchant, a KOH-based aqueous solution, was subsequently modified by addition of potassium peroxydisulphate (K₂S₂O₈), and later trisodium phosphate (Na₃PO₄) was added. The mechanism of photoetching in these solutions is presented and the advantages of using two- and three-component solutions are considered. This mechanism is based on generation of charge carriers (electrons and holes) by illumination of GaN with supra-bandgap light and was named photo-electrochemical (PEC) method. A correlation has been established between the carrier concentration in n-type GaN and the photoetch rate. A model is outlined that allows interpretation of large differences in the photoetch rate of inhomogeneous samples. Numerous examples of defects revealed by photoetching of GaN bulk crystals and homo- or hetero-epitaxial layers are described. The corresponding models for the formation of etch features are discussed and the results are compared with those obtained from other structural methods used for analysis of novel defects found in ammonothermally grown GaN crystals. The range of defects revealed by photoetching in GaN includes dislocations, inversion domains, nano-pipes, nano-scale and extended inhomogeneities. The importance of using photoetching for analysis of potentially new types of defect in recently grown ammonothermally GaN bulk crystals is emphasized. Future prospects of the PEC method for analysis of defects are considered.</p></div>","PeriodicalId":409,"journal":{"name":"Progress in Crystal Growth and Characterization of Materials","volume":"70 2","pages":"Article 100623"},"PeriodicalIF":5.1,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}