Готові списки джерел за темами / Cu2SnS3

Зміст

Статті в журналах
Дисертації
Частини книг
Тези доповідей конференцій

Добірка наукової літератури з теми "Cu2SnS3"

Автор: Grafiati

Опубліковано: 11 березня 2023

Оновлено: 6 вересня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Cu2SnS3".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Cu2SnS3"

Budanov, Alexander V., Yury N. Vlasov, Gennady I. Kotov, Evgeniy V. Rudnev та Pavel I. Podprugin. "Формирование тонких пленок соединений Cu2SnS3 и Cu2SnSe3". Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 21, № 1 (5 березня 2019): 24–29. http://dx.doi.org/10.17308/kcmf.2019.21/713.

Повний текст джерела

Анотація:

Показана возможность синтеза соединений Cu2SnS3 и Cu2SnSe3 на стеклянных подложках путём отжига в парах халькогена тонкой металлической плёнки сплава Cu:Sn = 2:1 в вакуумной графитовой камере типа квазизамкнутого объёма. Методом рентгеновской дифракции установлено, что полученные плёнки халькогенидов имеют подобную сфалериту кристаллическую структуру. Для кубической модификации Cu2SnS3 и Cu2SnSe3 преимущественными плоскостями отражений являются (111), (220) и (311). Элементный состав плёнок соответствует стехиометрии соединений Cu2SnS3 и Cu2SnSe3. Методом ИК-спектроскопии определены энергии активации прямозонных переходов для Cu2SnS3 – 0.96 eV, а для Cu2SnSe3 – 0.70 eV. ИСТОЧНИК ФИНАНСИРОВАНИЯ Работа выполнена при финансовой поддержке гранта РФФИ № 18-32-00971 – мол_а. ЛИТЕРАТУРА Milichko V. A., Shalin A. S., Mukhin I. S., et al. Usp., 2016, vol. 59, pp. 727–772. https://doi.org/10.3367/ufne.2016.02.037703 Wesley Herche. Renewable and Sustainable Energy Reviews, 2017, vol. 77, pp. 590-595. https://doi.org/10.1016/j.rser.2017.04.028 Rujun Suna, Daming Zhuang, Ming Zhao, et al. Solar Energy Materials and Solar Cells, 2018, vol. 174, pp. 42–49. https://doi.org/10.1016/j.solmat.2017.08.011 Orletskii I. G., Mar’yanchuk P. D., Solovan M. N., et al. Physics of the Solid State, 2016. vol. 58, no. 5, pp. 1058-1064. https://doi.org/10.1134/s1063783416050188 Ren Y. Acta Universitatis Upsaliensis, Uppsala, 2017, 85 p. URL: https://uu.diva-portal.org/smash/get/diva2:1072439/FULLTEXT01.pdf Lokhande A. C. Solar Energy Materials and Solar Cells, August 2016, vol. 153, pp. 84-107. https://doi.org/10.1016/j.solmat.2016.04.003 Shelke H. D., Lokhande A. C., Patil A. M., et al. Surfaces and Interfaces, 2017, vol. 9, pp. 238-244. https://doi.org/10.1016/j.surfin.2017.08.006 Orletskii I. G., Solovan M. N., Pinna F., et al. Physics of the Solid State. 2017, vol. 59, no. 4, pp. 801-807. https://doi.org/10.1134/s1063783417040163 Mingrui He. Journal of Alloys and Compounds, April 2017, vol. 701, pp. 901-908. https://doi.org/10.1016/j.jallcom.2017.01.191 Pin-Wen, GuanShun-Li Shang, Greta Lindwall. Solar Energy, 2017, vol. 155, pp. 745-757. https://doi.org/10.1016/j.solener.2017.07.017 Ju Yeon Lee. Solar Energy, 2017, vol. 145, pp. 27-32. https://doi.org/10.1016/j.solener.2016.09.041 Subbotina, O. Y., Kishkoparov N. V., Frishberg I. V. High Temperature, 1999, vol. 37, no. 2, pp. 198–203. URL: http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=tvt&paperid=2266&option_lang=rus (in Russ.) Budanov A. V., Vlasov Yu. N., Grechkina M. V., et al. Condensed Matter and Interphases, 2016, vol. 18, no. 4, pp. 481–486. URL: http://www.kcmf.vsu.ru/resources/t_18_4_2016_004.pdf (in Russ.) Zhang, Huang L. L., Zhu X. G., et al. Scripta Materialia, 2019, vol. 159, pp. 46–50. https://doi.org/10.1016/j.scriptamat.2018.09.010 Lukashev P., Lambrecht W. R. L., Kotani T., Schilfgaarde M. Rev. B: Condens. Matter Mater. Phys., 2007, vol. 76, p. 195202. https://doi.org/10.1103/physrevb.76.195202

Стилі APA, Harvard, Vancouver, ISO та ін.

Ahamed, M. I., M. Ahamed, A. Sivaranjani, and S. Chockalingam. "Energy bandgap studies on copper chalcogenide semiconductor nanostructures using cohesive energy." Chalcogenide Letters 18, no. 5 (May 2021): 245–53. http://dx.doi.org/10.15251/cl.2021.185.245.

Повний текст джерела

Анотація:

Investigating the properties of semiconductor nanomaterials to understand the specific behavior of nano-scale materials and predicts novel advancement of functionalized semiconductor materials that are influenced by cohesive energy. Cohesive energy is strongly associated with semiconductor nanomaterials as the energy increment by the arrangement of atoms in a crystal which is one of the most fundamental properties. In this communication, the shape and size dependence over the energy bandgap of copper chalcogenide semiconductor nanomaterials is investigated. The theoretical model is derived on cohesive energy of semiconductor nanomaterials was equated with the bulk materials. For this research, we considered Cu2SnS3, Cu2SnSe3, Cu2SnTe3, Cu3SbSe4, and CuSbS2 chalcogenide matters to the study of shape and size dependent-energy bandgap. The model forecasts that the energy bandgap is inversely proportional to the size of the semiconductor. The present modeling results are correlated with established experimental data and underpin the model reported.

Стилі APA, Harvard, Vancouver, ISO та ін.

Li, Cai Xia, Jun Guo, Danyu Jiang, and Qiang Li. "Synthesis and Characterization of Graphene/Cu₂SnS₃ Quantum Dots Composites." Advanced Materials Research 624 (December 2012): 59–62. http://dx.doi.org/10.4028/www.scientific.net/amr.624.59.

Повний текст джерела

Анотація:

In this paper, employing Cu(AC)2•H2O, SnCl2•2H2O and thiourea as raw materials, the composites of graphene/Cu2SnS3 quantum dots (QDs) were prepared simply and quickly using the hydrothermal method. Meanwhile, the separate Cu2SnS3 QDs were also synthesized in the same way. The as-obtained Cu2SnS3 QDs and composites’ phase structures were analyzed and characterized by powder X-ray diffraction (XRD), and the results indicated that the size of the Cu2SnS3 QDs in the composites were less than that of the separate Cu2SnS3 QDs. At the same time, their morphologies were also observed and cross-confirmed by Transmission Electron Microscopy (TEM), and the measurements manifested that Cu2SnS3 QDs were uniformly dispersed on the surface of the graphene, while the separate Cu2SnS3 QDs have obvious glomeration. In addition to this, elemental analysis was also made to verify the existence of Cu2SnS3 on the surface of graphene.

Стилі APA, Harvard, Vancouver, ISO та ін.

Rzaguliyev, Vidadi A., Oruj S. Kerimli, Dilbar S. Ajdarova, Sharafat H. Mammadov та Ozbek M. Aliev. "Фазовые равновесия в системах Ag8SnS6–Cu2SnS3 и Ag2SnS3–Cu2Sn4S9". Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 21, № 4 (19 грудня 2019): 544–51. http://dx.doi.org/10.17308/kcmf.2019.21/2365.

Повний текст джерела

Анотація:

Комплексными методами физико-химического анализа (дифференциально-термический, рентгенофазовый, микроструктурный, измерение микротвердости и определение плотности) изучены фазовые равновесия и построены Т–х фазовые диаграммыв системах Ag8SnS6–Cu2SnS3 и Ag2SnS3–Cu2Sn4S9. Показано, что система Ag8SnS6–Cu2SnS3является квазибинарным сечением квазитройной системы Ag2S-SnS2-Cu2S и относится кпростому эвтектическому типу с ограниченными областями растворимости на основеисходных сульфидов. Координаты эвтектической точки: 50 mol % Ag2SnS3 И Т = 900 К.Растворимость на основе Ag8SnS6 и Cu2SnS3 при эвтектической температуре простираетсядо 20 и 28 mol % соответственно. С уменьшением температуры твердые растворы распадаются и при 300 К составляют 5 и 10 mol %. Установлено, что с увеличением концентрацииAg8SnS6 в твердых растворах (Cu2SnS3)1-х (Ag8SnS6)х параметр кубической решетки увеличивается от а = 0.5445 nm (для чистого Cu2SnS3) до а = 0.725 nm (для состава х = 0.1) т. е. концентрационная зависимость параметра решетки имеет линейный характер.Система Ag2SnS3–Cu2Sn4S9 из-за перитектического плавления Cu2Sn4S9 имеет сложный характер и является частично квазибинарным сечением. Квазибинарность нарушается вобласти концентрации 65-100 mol % Cu2Sn4S9 и выше температуры 900 К. Твердые растворына основе Ag2SnS3 и Cu2Sn4S9 узкие и при 300 К составляют 10; 2.5 mol % соответственно ЛИТЕРАТУРА1. Wang N., Fan A. K. An experimental study of the Ag2S-SnS2 pseudobinary join // Neues Jahrb. Mineral.-Abh, 1989, v. 160, pp. 33–36.2. Wang N. New data for Ag8SnS6 (canfeildite) and Ag8GeS6 (argyrodite) // Neues Jahrb. Mineral. Monatsh.,1978, pp. 269–272.3. Бабанлы М. Б., Юсибов Ю. А., Абишев В. Т. Трехкомпонентные халькогениды на основе медии серебра. Баку: Изд-во БГУ, 1993, 342 с.4. Parasyuk O. V., Chykhrij S. I., Bozhko V. V., Piskach L. V., Bogdanyuk M. S., Olekseyuk I. D.,Bulatetska L. V., Pekhnyo. Phase diagramm of the Ag2S–HgS–SnS2 system and single crystal prepartion,crystal structure and properties of Ag2HgSnS4 // J. Alloys and Compounds, 2005, v. 399, pp. 32–37. DOI: https://doi.org/10.1016/j.jallcom.2005.03.0085. Olekseyuk I. D., Dudchak I. B., Piskach L. V. Phase equilibria in the Cu2S–ZnSe–SnS2 // J. Alloys andCompounds, 2004, v. 368, pp. 135–143. https:doi.org/10.1016/j.jallcom.2003.08.0846. Ollitrault-Fitchet R., Rivet J., Flahaut J., et.al. Description du systeme ternaire Ag–Sn–Se // J. Less-Common. Met., 1988, v. 138(2), pp. 241–261. DOI:https://doi.org/10.1016/0022-5088(88)90113-07. Delgado C. E., Mora A. J., Marcano E. Crystal structure refi nement of the semiconducting compoundCu2SnSe3 from X-ray powder difraction data // Mater. Res. Bull., 2003, v. 38, pp. 1949–1955. DOI: https://doi.org/10.1016/j.materresbull.2003.09.0178. Parasyuk O. V., Olekseyuk I. D., Marchuk O. V. The Cu2Se–HgSe–SnSe2 // J. Alloys and Compounds.,1999, v. 287, pp. 197–205. DOI: https//doi.org/10.1016/S0925-8388(99)00047-X9. Parasyuk O. V., Gulay L. D., Piskach L. V., Kumanska Yu. O. The Ag2Se–HgSe–SnSe2 system and thecrystal structure of the Ag2HgSnSe4 // J. Alloys and Сompounds, 2002, v. 339, pp.1 40–143. DOI: https//doi.org/10.1016/S0925-8388(01)01985-510. Babanly M. B., Yusibov Y. A., Babanly N. B. Electromotive force and measucement in several systema.Ed. by S. Kara, Intechneb. Org., 2011, pp. 57–58.11. Gulay L. D., Olekseyuk I. D., Parasyuk O. V. Crystal structure of b-Ag8SnSe6 // J. Alloys and compounds,2002, v. 339, pp. 113–117. DOI: https//doi.org/10.1016/S0925-8388(01)01970-312. Гусейнов Г. М. Получение соединения Ag8SnS6 в среде диметилформамида // Вестн. Томского гос. ун-та. Химия, 2016, № 1(3), c. 24–34. Режим доступа: fi le:///C:/Users/Lab351/Downloads/sub_%20%20in%20dimethylformamide%20medium.pdf (дата обращения: 19.09.2019)13. Gorchov O. Les composes Ag8MX6 (M = Si, Ge, Sn et X = S, Se, Te) // Bull. Soc. Chim. Fr., 1968, № 6.pp. 2263–2275.14. Kokhan O. P. The Interactions in Ag2X–BIVX2 (BIV – Si, Ge, Sn; X – S, Se) systems and the propertiesof compounds. Doctoral Thesis, Uzhgorod, Uzhgorod State Univ., 1996.15. Onoda U., Chen X. A., Sato A., Wada H. Crystal structure and twinning of monoclinic Cu2SnS3 // Mater.Res. Bull., 2000, v. 35, № 8, pp. 1563–1570. DOI: https//doi.org/10.1016/S0025-5408(00)00347-016. Рзагулиев В. А., Керимли О. Ш., Мамедов Ш. Г. Изучение квазитройной системы Ag2S–SnS2–Cu2S по разрезу Ag8SnS6–Cu2SnS3. Труды Международ. научно–практич. конф., Россия, Белгород,2019, c. 18.17. Рзагулиев В. А., Керимли О. Ш., Маме дов Ш. Г. Исследование квазибинарного разреза Cu2SnS3–Ag2SnS3 в квазитройной системеAg2S–Cu2S–SnS2 . Труды XXI Междун. конф., Санкт-Петербург, 2019,c. 20–21.18. Цигика В. В., Переш Е. Ю., Лазарев В. В. и др. Получение и свойства мнонокристаллов соединений/TlPbJ3, Tl3PbJ5, TlSnJ3, TlSn2J5 and Tl3PbBr5 Изв. АН СССР. Неорган. материалы, 1981, т. 17(6), c. 970–974.

Стилі APA, Harvard, Vancouver, ISO та ін.

Pogue, Elizabeth A., Melissa Goetter, and Angus Rockett. "Reaction kinetics of Cu2-xS, ZnS, and SnS2 to form Cu2ZnSnS4 and Cu2SnS3 studied using differential scanning calorimetry." MRS Advances 2, no. 53 (2017): 3181–86. http://dx.doi.org/10.1557/adv.2017.384.

Повний текст джерела

Анотація:

ABSTRACTDifferential scanning calorimetry experiments on mixed Cu2-xS, ZnS, and SnS2 precursors were conducted to better understand how Cu2ZnSnS4 (CZTS) and Cu2SnS3 form. The onset temperatures of Cu2SnS3 reactions and CZTS suggest that the ZnS phase may mediate Cu2SnS3 formation at lower temperatures before a final CZTS phase forms. We also found no evidence of a stable Cu2ZnSn3S8 phase. The major diffraction peaks associated with Cu2ZnSnS4, and Cu2SnS3 (overlaps with ZnS, as well) began to grow around 380 °C, although the final reaction to form Cu2ZnSnS4 probably did not occur until higher temperatures were reached. An exothermic reaction was observed corresponding to formation of this phase. There was some variability in the onset temperature for reactions to form Cu2SnS3. At least 5 steps are involved in this reaction and several segments of the reaction had relatively reproducible energies.

Стилі APA, Harvard, Vancouver, ISO та ін.

Irshad Ahamed, M., and K. Sathish Kumar. "Studies on Cu2SnS3 quantum dots for O-band wavelength detection." Materials Science-Poland 37, no. 2 (June 1, 2019): 225–29. http://dx.doi.org/10.2478/msp-2019-0022.

Повний текст джерела

Анотація:

AbstractIn this communication, we report on Cu2SnS3 quantum dots synthesized by the solvothermal process using different solvents. The optical properties of the quantum dots are analyzed by UV-Vis-NIR and photoluminescence spectroscopy. The results suggest that Cu2SnS3 material has tunable energy bandgap and appropriate wavelength for fabrication of light emitting diodes and laser diodes as sources for fiber optic communication. They exhibit wide absorption in the near infrared range. Further morphological studies with the use of atomic force microscope confirm the surface topography and the existence of quantum dots. The observed characteristics prove the efficiency of Cu2SnS3 quantum dots for O-band wavelength detection used in fiber optic communication and solar cell applications.

Стилі APA, Harvard, Vancouver, ISO та ін.

BUDANOV, A. V., YU N. VLASOV, G. I. KOTOV, YU V. SYNOROV, S. YU PANKOV, E. V. RUDNEV, V. E. TERNOVAYA, and S. A. IVKOV. "HETEROJUNCTION p-Cu2SnS3/n-ZnO." Chalcogenide Letters 17, no. 9 (September 2020): 457–59. http://dx.doi.org/10.15251/cl.2020.179.457.

Повний текст джерела

Анотація:

Conditions for the formation of a Cu2SnS3 film uniform in phase composition upon annealing of a metal layer of copper and tin in sulfur vapor in a quasi-closed volume chamber using the methods of X-ray spectral microanalysis and X-ray phase analysis are presented. The rectifying heterojunction p-Cu2SnS3/n-ZnO was fabricated. PACS numbers: 81.20.−n, 61.10.Nz, 84.60.Jt

Стилі APA, Harvard, Vancouver, ISO та ін.

Mammadov, Sharafat Gadzhiaga. "Phase formation in the Cu2SnS3-Sb2S3 system." Vestnik Тomskogo gosudarstvennogo universiteta. Khimiya, no. 18 (June 1, 2020): 18–26. http://dx.doi.org/10.17223/24135542/18/2.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Mammadov, Sharafat G. "Phase equilibrium in Cu2SnS3-Cu3SbS3 system." Vestnik Тomskogo gosudarstvennogo universiteta. Khimiya, no. 15 (December 1, 2019): 26–35. http://dx.doi.org/10.17223/24135542/15/3.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

de Wild, Jessica, Erika V. C. Robert, Brahime El Adib, and Phillip J. Dale. "Optical characterization of solution prepared Cu2SnS3 for photovoltaic applications." MRS Proceedings 1771 (2015): 151–56. http://dx.doi.org/10.1557/opl.2015.624.

Повний текст джерела

Анотація:

ABSTRACTMonoclinic Cu2SnS3 was made by solution based processing of the precursor metals after which the samples are annealed in a sulphur environment. XRD and Raman spectra shows that the monoclinic phase was synthesised. One sample was further etched in KCN and HCl to remove possible secondary phases. Transmission spectra show that the material has two optical transitions and in conjunction with reflection data absorption spectra were calculated. The two optical transitions are determined to be 0.91 and 0.98 for the unetched sample and 0.90 and 0.95 eV for the etched sample. The values of the optical transitions are within the error the same and thus etching does not affect the values of these optical transitions. Photoluminescence spectra map show only one luminescence peak with a maximum at 0.95 eV, which is consistent with the values found by absorption spectra. This in combination with the Raman spectra and XRD indicates that the sample contains only one polymorph of Cu2SnS3, which is monoclinic. Therefore the two optical transitions are intrinsic to monoclinic Cu2SnS3.

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Дисертації з теми "Cu2SnS3"

Lohani, Ketan. "Development of Cu2SnS3 based thermoelectric materials and devices." Doctoral thesis, Università degli studi di Trento, 2022. http://hdl.handle.net/11572/344345.

Повний текст джерела

Анотація:

Commercially available high-performance thermoelectric materials are often rare or toxic and therefore unsustainable. The present thesis work makes a case for eco-friendly, earth-abundant, and non-toxic p-type ceramic Cu2SnS3 (CTS, hereafter) and, in general, the use of disordered materials for thermoelectric applications. The detailed study of polymorphism, synthesis conditions, porosity, grain size, and doping provides a systematic and in-depth experimental and computational analysis of thermoelectric properties and stability of CTS. These results can be generalized for numerous thermoelectric materials and other applications. Moreover, a case for functioning thermoelectric generators using non-toxic and cost-effective materials is also presented. The thesis begins with a brief introduction to thermoelectricity, followed by a literature review and justification of the choice of the subject. The second chapter puts forward a novel approach to stabilize a disordered CTS polymorph without any chemical alteration through high-energy reactive ball milling. The third chapter deals with the stability of disordered samples under different synthesis and sintering conditions, highlighting the effect of synthesis environment, microstructure, and porosity. The fourth chapter employed a novel, facile, and cost-effective two-step synthesis method (high-energy ball milling combined with spark plasma sintering) to synthesize CTS bulk samples. The two-step synthesis method was able to constrain the CTS grain growth in the nanometric range, revealing the conductive nature of the CTS surfaces. The next chapter explores combining the two-step synthesis method with Ag substitution at the Sn lattice site to improve CTS's thermoelectric performance further. In the final stages of the thesis work, thin film thermoelectric generators were fabricated using CTS and similar chalcogenides, demonstrating power output comparable to existing thermoelectric materials used in the medium temperature range. The final chapter summarizes outlooks and future perspectives stemming from this research work.

Стилі APA, Harvard, Vancouver, ISO та ін.

Marquez, Prieto Jose. "Development of Cu2ZnSnSe4 and Cu2SnS3 based absorbers by PVD processes." Thesis, Northumbria University, 2016. http://nrl.northumbria.ac.uk/36010/.

Повний текст джерела

Анотація:

Kesterite thin film solar cells are one of the most promising technologies for the future thin film PV market. The term “kesterite” refers to the crystal structure that the Cu2ZnSn(S,Se)4 compound adopts. This thesis discusses the study of the formation of the pure selenide of the kesterite compound Cu2ZnSnSe4 (CZTSe) as an absorber layer. The layers were produced by a 2-stage physical vapour deposition (PVD) of Cu-Zn-Sn precursor films by sputtering followed by a reactive conversion step in the presence of Se. Solar cells have been fabricated with the absorbers produced. The research explored the evolution of phases during the formation of CZTSe and the influence of the absorber composition on its optical and microstructural properties. In addition, the work involved: optimisation of the CZTSe synthesis process, studying the influence of the Se source, the role of temperature of the conversion process, the role of ramping rate and the ambient pressure, and the role of these for maximising device performance. From the study of the evolution of phases it was concluded that CZTSe can be formed from Cu-Zn-Sn precursors over a wide range of temperatures (380-550 oC). The formation of the ternary compound Cu2SnSe3 (CTSe) from Cu-Sn precursors using the same synthesis approach was also demonstrated. Whilst this material was considered unsuitable as a solar PV absorber layer due to its low bandgap, the pure sulphide ternary phase Cu2SnS3 (CTS) was considered more suitable and was synthesised using a single step co-evaporation PVD method. A device with an efficiency of 1.8% demonstrated the possibility of using this earth abundant compound for thin film PV. A combination of X-ray diffraction and Raman spectroscopy studies demonstrated that CZTSe films with very Cu-poor and Zn-rich compositions led to a high population of the beneficial VCu + ZnCu defect clusters, and CZTSe phase domains with a less disordered kesterite type structure. This led to devices with efficiencies over 8% and VOC values greater than those of the current world record CZTSe solar cells. The research of this thesis provides a combination of practical and fundamental knowledge that could become a key towards minimising the efficiency gap between kesterites and their commercialised chalcogenide predecessors: CdTe and Cu(In,Ga)Se2.

Стилі APA, Harvard, Vancouver, ISO та ін.

Belaqziz, Mohamed. "Association des procédés hydrothermal et CVD à courte distance pour l'élaboration de couches minces photovoltaiques à partir d'une source nanostructurée du composé Cu2SnS3." Thesis, Perpignan, 2018. http://www.theses.fr/2018PERP0007/document.

Повний текст джерела

Анотація:

Le materiau Cu2SnS3 (CTS) est un semi-conducteur caracterisé par une bande interdite direct et un fort coefficient d'absorption optique dans le domaine du visible. Ces propriétés font de lui un des composes les plus attractifs pour une application photovoltaïque en couches minces. Compare aux technologies concurrentes, le CTS tire ces principaux avantages du nombre et de la nature de ses éléments. Ils sont abondants et non toxiques, une tendance encourageante qui promet de développer une future technologie de photopiles a faible cout et respectueuse de l’environnement. L’objectif de ce travail est de réaliser des dépôts de films minces microstructures de CTS a partir de nanoparticules du même matériau. Pour se faire, un protocole expérimental original a été adopte en associant deux procédés d’élaboration simple : hydrothermal et CVD a courte distance. Cette approche a permis de s’affranchir des procédés conventionnels couteux actuellement employés
The Cu2SnS3 compound (CTS) is a semiconductor characterized by a direct band gap and a high optical absorption coefficient in the visible range. These properties make it one of the most attractive materials for thin-film photovoltaic (PV) applications. Compared to competing technologies, CTS derives its main benefits from the number and nature of its constituent elements. They are abundant and non-toxic. This encouraging trend is propitious for the development of future low cost and environmentally friendly solar cell technology. The aim of our study is to develop CTS thin films from the same nanostructured source material. To this end, we have have developed an original experimental procedure, by combining two simple, low-cost and environmentally friendly processes: Hydrothermal and Short-Range CVD. This approach has made it unnecessary to use the conventional costly processes presently employed

Стилі APA, Harvard, Vancouver, ISO та ін.

Доброжан, Олександр Анатолійович, Александр Анатольевич Доброжан, Oleksandr Anatoliiovych Dobrozhan, Анатолій Сергійович Опанасюк, Анатолий Сергеевич Опанасюк та Anatolii Serhiiovych Opanasiuk. "Синтез нанокристалических тетраподов Cu2SnSe3". Thesis, Издательство ЮЗГУ, Курск, Россия, 2014. http://essuir.sumdu.edu.ua/handle/123456789/38313.

Повний текст джерела

Анотація:

В работе с помощью коллоидального синтеза были получены наноразмерные тетраподы трехкомпонентного соединения Cu2SnSe3. Методами просвечивающей электронной микроскопии, рентгенодифрактометрии, рентгеноспектрального анализа были изучены морфология, структурные свойства и элементный состав, полученных наночастиц. Установлено, что трехмерные частицы имели форму ядра с симметрично расположенными четырьмя выростами - «руками». Рентгено-дифрактометрический анализ показал присутствие в наночастицах с элементным составом Cu1.83Sn0,86Sn3 сфалеритной и вюрцитной фаз.
In work Cu2SnSe3 nanotetrapods using colloidal synthesis were obtained. By transmission electron microscopy, X-ray diffractometry, energy dispersive spectroscopy were studied morphological, structural properties and chemical composition of the obtained ternary chalcogenide zinc (Cu2SnSe3). The nanoparticles had the form of a core with symmetrically arranged 4 "hands". X-ray diffraction analysis showed the presence sphalerite and wurtzite phases in nanoparticles with the elemental composition Cu1,83Sn0,86Sn3

Стилі APA, Harvard, Vancouver, ISO та ін.

Chang, Shih-Chang, and 張世昌. "Synthesis of Cu2SnS3 and Cu2SnSe3 Absorbers for Thin-Film Solar Cell by Solvent-Thermal Refluxing Method and Annealing." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/5dmc8c.

Повний текст джерела

Анотація:

碩士
國立臺南大學
電機工程學系碩博士班
103
In this study, we investigated the ternary I–IV–VI compounds semiconductor layer synthesized by a simple and low-cost solvent-thermal refluxing method follow annealing. The thin films are suitable to be absorber layer of solar cells. At first, we fabricated the varied concentration of Cu-Sn-S precursor ink. After sulfurization, we obtained pure phase of CTS by sulfurizing the Cu-Sn-S precursor of the lower concentration. The CTS thin film is p-type with a carrier concentration of ∼5.23×1017 cm-3, and hole mobility of 14.2 cm2 V−1 s−1, which is suitable to be absorber layer of solar cells. We fabricated the Cu-Sn-Se precursor ink by different reaction time. At the longer reaction time, we obtained pure phase of CTSe. At the shorter reaction time, we obtained Cu2-xSe crystals and unformed Cu-Sn-Se groups. After selenization, the structures of Cu2SnSe3 were destructured and binary CuSe appeared. In contrast, after selenization, the precursors of short reaction time transform into pure Cu2SnSe3. The CTSe thin film is p-type with a carrier concentration of ∼1.9×1017 cm−3, and higher hole mobility of 13.66 cm2 V−1 s−1, which is suitable to be absorber layer of solar cells. In this study, we fabricated the ternary I–IV–VI compounds thin films by a simple and low-cost solvent-thermal refluxing method and and annealing.

Стилі APA, Harvard, Vancouver, ISO та ін.

Saragih, Albert Daniel, and Albert Daniel Saragih. "Investigation of Cu2SnSe3 and Mg-doped Cu2SnSe3 Thin Films for Photovoltaic Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/22800329344533239817.

Повний текст джерела

Анотація:

碩士
國立臺灣科技大學
材料科學與工程系
103
Due to the energy crisis, we rush into the solar cell research and development. Fulfillment of energy is an issue that is always covered by each of the countries, coupled with the increasing rate of world population growth the energy consumption will continue to increase. Solar cell is one of the best choices, solar cells has been studied for more than fifty years but the last decade has seen the drastic growth in the research and development in the sector and because of that, now we have so many different types of solar cells design with megawatt production capabilities. Modern solar cells design can be fabricated using different materials and can have different structure. Cu2SnSe3 (CTSe) is a potential candidate for absorber materials of solar cells. In this study, we report the effects of doping Mg on the structural, electrical, and optical properties of these CTSe thin films for devolepment of highly efficient solar cells for long term energy production. Thin films of the CTSe and Mg-doped CTSe were sputtered with two different targets of Cu and Sn or Cu-Mg and Sn, respectively , followed by the selenization at 500-600 oC under the Se vapor. The films were characterized by FE-SEM, EDS, XRD, and Hall measurement and other analyses to explore the effects of Mg-doping with different ratios on CTSe thin film. All the thin films CTSe and Mg-doped CTSe were deposited by DC magnetron co-sputtering at room temperature with the powers of 26 W for Cu target and 16 W for Sn target for CTSe thin films and 26 W for Cu-Mg target and 16 W for Sn target for Mg-CTSe for 1hour. A two-step selenization process was executed at 300 oC and holding period of 30 min before reaching to three different selenization temeperatures of 500 oC, 550 oC, and 600 oC. The selenization procedure had been done in Se ambient arisen from SnSe2 pellet. Almost all thin films selenized at 550 oC-selenized films had the composition closed to expected stoichiometry of Cu2SnSe3. The major XRD diffraction peaks appeared at 2θ of 26.8°, 44.8°, 53.2°, 65.5°, and 72.3° which could be attributed to (111), (220), (311), (400), and (331) planes, respectively. All the diffraction peaks of CTSe could be assigned to the crystal planes from standard structure of Cu2SnSe3 (JCPDS No.89-2879). The optical band gaps obtained by extrapolating the linear region of the absorption spectra did not significantly change. The optical absorption studies indicated a direct band gap of 1.18 ~ 1.20 eV. Undoped CTSe and Mg-0.1-CTSe films selenized at 550 oC exhibited p-type conductivity and they were n-type for Mg-0.2-CTSe and Mg-0.3-CTSe. The Hall measurements for carrier concentration and Hall mobility were 2.54×1019 cm−3 and 681 cm2V−1s−1, respectively, for undoped CTSe film, 9.08 ’ 1018 cm-3 and 71 cm2V-1s-1 for Mg-0.1-CTSe, 1.18 ’ 1019cm−3 and 11 cm2V−1s−1 for Mg-0.2-CTSe, and 1.06 ’ 1019cm−3 and 43 cm2V−1s−1 for Mg-0.3-CTSe, after selenization at 550 oC.

Стилі APA, Harvard, Vancouver, ISO та ін.

Huang, Wei-di, and 黃瑋迪. "Preparation and characterization of sputtered Cu2SnSe3 thin films." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/04908759369258486576.

Повний текст джерела

Анотація:

碩士
國立臺灣科技大學
材料科技研究所
97
Recently, the research of solar cells is much more attractive and its technological progress is very fast. Although solar cells have reached a good conversion efficiency, high cost has limited their further applications. Lowering the cost with the finding of new materials is necessary. Although there are many CuInSe2 replacements, low-cost Cu2SnSe3 thin films with an energy band gap of 0.7-0.9 eV have not been seriously investigated for the absorption layer of the solar cells. In this study, the effects of the target composition, substrate temperature, annealing temperature, and the Se compensating discs on the sputtered Cu2SnSe3 thin films are discussed. The physical characteristics of the Cu2SnSe3 thin films were invstigated by XRD, FE-SEM, and EDS XRD. Hall measurement and Absorption spectroscopy were used for the electrical and optical properties, respectively. The experimental results shows that the sputtered Cu2SnSe3 thin films deposited at 400oC followed by annealing at 500oC have a better performance. At this condition, the films are p-type and have well crystallized with a large grain size of 1-3 �慆, a direct energy gap of 0.7-0.8 eV, an absorption coefficient of 104 cm-1 before and after annealing, a carrier concentration of 5×1019 cm-3, and the highest carrier mobility of 8~10 cm2V-1s-1.

Стилі APA, Harvard, Vancouver, ISO та ін.

Chang, Chia-Chi, and 張佳祺. "Electrical and thermal transport properties of Sb doped Cu2SnSe3." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8xq5pw.

Повний текст джерела

Анотація:

碩士
國立東華大學
物理學系
105
The effect of Sb doping on the thermoelectric properties including electrical resistivity, thermal conductivity, and Seebeck oefficient of Cu2SnSe3 has been studied in the temperature range of 10 - 400 K. Besides, thermoelectric performance of the Cu2Sn1-xSbxSe3 (0 ≤ x ≤ 0.04) series with different preparation processes, i.e. conventional solid state route and spark plasma sintering (SPS), is compared. For samples prepared by conventional solid state route, electrical resistivity is found to decrease with increase in Sb content up to x = 0.02, then it increases with further increase in x. The Seebeck coefficient for all samples is positive, indicating that the dominant charge carries are holes. The thermal conductivity is found to decrease with increase in Sb concentration, presumably due to point-defect scattering as a result of Sb substitution. The electronic thermal conductivity κe is estimated to be about 1% of the total thermal conductivity, suggesting that the thermal conduction is mainly associated with lattice thermal conductivity κL. The highest value of figure of merit at 400 K is equal to 0.0137 for the sample Cu2Sn0.99Sb0.01Se3 which is about eight times greater than that of the pristine sample. It is observed that electrical resistivity for all the samples prepared by SPS technique is reduced considerably than the samples prepared by solid state reaction method, which is favorable in enhancing ZT because the electrical resistivity should be low for good thermoelectric materials. It is also noted that the Seebeck coefficient for samples prepared by SPS are significantly enhanced in comparison with the samples prepared by solid state reaction method. In particular, Seebeck coefficient of the x = 0.01 sample is about 295 μV/K at 400 K, which is about two times greater than that of the sample prepared by solid state reaction method. In addition, it is clearly seen that thermal conductivity values for samples prepared using SPS method are larger than that of samples prepared using solid state reaction method, demonstrating that SPS could produce denser samples with a better crystallinity. The maximum ZT value reaches 0.046 at 400 K for the Cu2Sn0.96Sb0.04Se3 sample, which is about 18 times greater than the sample prepared by solid state reaction method. In conclusion, it is found that the presently studied Cu2Sn1-xSbxSe3 (0 ≤ x ≤ 0.04) samples prepared by SPS exhibits a better thermoelectric performance than solid state route.

Стилі APA, Harvard, Vancouver, ISO та ін.

Hong, Yu Chen, and 洪郁宸. "Preparation and characterization of Cu2SnSe3 powders using solution growth technology." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/nmqfjt.

Повний текст джерела

Анотація:

碩士
長庚大學
化工與材料工程學系
104
In this study, the ternary Cu2SnSe3 semiconductor thin films were prepared using the thermal treatment of Cu2SnSe3 particles obtained from solution growth technology. The effects of Cu/Sn molar ratios in samples on the structural, electrical, and optical properties of the samples were investigated. The average particle size of the samples decreased with an increase in [Sn]/[Cu] molar ratio. X-ray diffraction pattern(XRD) and energy dispersive analysis of X-ray(EDAX) show that there were Se vacancies when the annealing temperature is higher than 450°C and the optimal annealing temperature is 410°C. The crystal phase of the films changed from cubic-Cu2Se to cubic-Cu2SnSe3 with an increase in [Sn]/[Cu] molar ratio. The direct energy band gaps of thin films varied from 0.98~1.10eV, respectively, depending on [Sn]/[Cu] molar ratio in samples. From the Hall measurement analysis, the carrier concentration decreased and the resistivity increased with an increase in [Sn]/[Cu] molar ratio in samples. Hall measurement showed the conduction type of samples (A) and (B) were p-type, but samples (C)~(E) were n-type. The flat band potentials of samples were in the range of -0.56～-0.13V(vs. Normal hydrogen electrode, NHE) in the 0.5M K2SO4 solution obtained using Mott-Schottky measurements. The Maximum photoelectrochemical performance of samples reached to 0.24 mA/cm2 at the external potential of +0.4 V(vs. Ag/AgCl) in the 0.5M K2SO4 solution.

Стилі APA, Harvard, Vancouver, ISO та ін.

Sousa, Afonso Pereira Correia de. "Investigation of detection limits of ZnSe and Cu2SnSe3 secondary phases in Cu2ZnSnSe4." Master's thesis, 2016. http://hdl.handle.net/10316/31589.

Повний текст джерела

Анотація:

Dissertação de Mestrado em Engenharia Física apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
Quaternary Cu2ZnSnSe4 (CZTSe) is a promising semiconductor material for absorber layer in thin lm solar cells due to direct band gap around 1eV and high absorption coe cient (> 104cm1) (7). The highest conversion e - ciency of CZTSe solar cells is above 11% (8). Nevertheless, a low open circuit voltage with respect to the band gap is a common phenomenon in CZTSe photovoltaic devices. A plausible reason for this is a reduction in the e ective band gap due to inhomogeneities in structure, phase, or composition. To gain a detailed knowledge of the in uence of phase inhomogeneities on the performance of solar cells, the understanding of detection limits of conventionally used characterization methods is essential. The aim of this work is to study the sensitivity limits of X-ray di raction and Raman spectroscopy to the presence of two very common secondary phases for Cu2ZnSnSe4{ZnSe and Cu2SnSe3. Polycrystalline powder of two CZTSe samples (slightly Zn-rich) and one Cu2SnSe3 sample have been grown using the solid state reaction method in evacuated silica tubes. Additionally, an industrially produced powder of ZnSe has been used to produce a number of mixtures of corresponding CZTSe with 1%, 2%, 3%, 5%, 10% and 20% of ZnSe or Cu2SnSe3 respectively. The structural characterization of the starting materials as well as of mixtures was carried out by powder X-ray di raction (PXRD) and subsequent Rietveld analysis of the di raction data using the FullProf suite (11). Rietveld re nement of di raction data of the mixtures was performed, paying a special attention to the in uence of amounts of ZnSe and Cu2SnSe3 on the di raction patterns of the mixtures. The amounts of secondary phases determined by Rietveld re nement have been compared with the initial data, determining in this way the detection limits of PXRD for these secondary phases. To study the crystal structure of the synthesized mixtures at the micrometer scale Raman spectroscopy has been employed. In these measurements a 632:8nm laser line was employed and it was found to be e cient for both ZnSe and Cu2SnSe3 phase detection. By performing Raman line scan measurements we evaluated characteristic Raman mode intensities corresponding to the di erent phases and thus are able to estimate the mixture composition.

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Частини книг з теми "Cu2SnS3"

Mammadov, A. N., I. Dz Alverdiev, Z. S. Aliev, D. B. Tagiev, and M. B. Babanly. "Thermodynamic Modeling of the Phase Diagram for Cu2SnS3-Cu2SnSe3 System." In Advances in Intelligent Systems and Computing, 888–95. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-35249-3_118.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Lokhande, A. C., V. C. Karade, V. C. Lokhande, C. D. Lokhande, and Jin Hyeok Kim. "Chemical Processing of Cu2SnS3 Nanoparticles for Solar Cells." In Chemically Deposited Metal Chalcogenide-based Carbon Composites for Versatile Applications, 271–95. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-23401-9_10.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Amiri, Iraj Sadegh, and Mahdi Ariannejad. "Copper Tin Sulfide (CU2SnS3) Solar Cell Structures and Implemented Methodology." In SpringerBriefs in Electrical and Computer Engineering, 37–47. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17395-1_3.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Villars, P., K. Cenzual, J. Daams, R. Gladyshevskii, O. Shcherban, V. Dubenskyy, V. Kuprysyuk, O. Pavlyuk, I. Savysyuk, and S. Stoyko. "Cu2SiS3." In Structure Types. Part 7: Space Groups (160) R3m - (156) P3m1, 697. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-69949-1_283.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Roy, Devsmita, Rajeshwari Garain, Arindam Basak, Subrat Behera, Ranjeeta Patel, and Udai P. Singh. "Impact of Performance Parameters on the Efficiency of Cu2SnS3 (CTS)/Si Tandem Solar Cell by SCAPS-1D." In Lecture Notes in Electrical Engineering, 63–75. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6605-7_5.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Chihara, H., and N. Nakamura. "NQRS Data for Cu2SnU (Subst. No. 2124)." In Substances Containing C10H16 … Zn, 996. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-02943-1_859.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Rahaman, Sabina, Jagannatha K. B., Thyagaraj Tanjavur, and Lakshmisagar. "Investigating the Effect of Annealing on the Properties of Cu2SnS3 Thin Films Using Spin Coating." In Current Approaches in Science and Technology Research Vol. 14, 106–11. Book Publisher International (a part of SCIENCEDOMAIN International), 2021. http://dx.doi.org/10.9734/bpi/castr/v14/2562f.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Cu2SnS3"

Kuku, Titilayo A., and Olaosebikan A. Fakolujo. "Photovoltaic Characteristics Of Thin Films Of Cu2SnS3." In 1986 International Symposium/Innsbruck, edited by Claes-Goeran Granqvist, Carl M. Lampert, John J. Mason, and Volker Wittwer. SPIE, 1986. http://dx.doi.org/10.1117/12.938349.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

de Wild, Jessica, Erika V. C. Robert, and Phillip J. Dale. "Chemical stability of the Cu2SnS3/Mo interface." In 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). IEEE, 2016. http://dx.doi.org/10.1109/pvsc.2016.7749626.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Lahlali, S., M. Belaqziz, H. Chehouani, L. Essaleh, K. Djessas, and K. Medjnoun. "Low temperature electrical conduction in thin film Cu2SnS3." In 2016 International Renewable and Sustainable Energy Conference (IRSEC). IEEE, 2016. http://dx.doi.org/10.1109/irsec.2016.7984081.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Patel, Biren, Manmohansingh Waldiya, Ranjan K. Pati, Indrajit Mukhopadhyay, and Abhijit Ray. "Spray pyrolyzed Cu2SnS3 thin films for photovoltaic application." In 2ND INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2017). Author(s), 2018. http://dx.doi.org/10.1063/1.5033015.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Patel, Biren, R. Narasimman, Ranjan K. Pati, Indrajit Mukhopadhyay, and Abhijit Ray. "Preparation and characterization of Cu2SnS3 thin films by electrodeposition." In INTERNATIONAL CONFERENCE ON NANOMATERIALS FOR ENERGY CONVERSION AND STORAGE APPLICATIONS: NECSA 2018. Author(s), 2018. http://dx.doi.org/10.1063/1.5035248.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zakutayev, Andriy, Lauryn L. Baranowski, Adam W. Welch, Colin A. Wolden, and Eric S. Toberer. "Comparison of Cu2SnS3 and CuSbS2 as potential solar cell absorbers." In 2014 IEEE 40th Photovoltaic Specialists Conference (PVSC). IEEE, 2014. http://dx.doi.org/10.1109/pvsc.2014.6925421.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Tiwari, Devendra, T. K. Chaudhuri, T. Shripathi, and U. Deshpande. "Cu2SnS3 as a potential absorber for thin film solar cells." In SOLID STATE PHYSICS: Proceedings of the 56th DAE Solid State Physics Symposium 2011. AIP, 2012. http://dx.doi.org/10.1063/1.4710361.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Raja, V. Sundara, U. Chalapathi, and S. Uthanna. "Growth and characterization of Cu2SnS3 thin films by spray pyrolysis." In INDIAN VACUUM SOCIETY SYMPOSIUM ON THIN FILMS: SCIENCE AND TECHNOLOGY. AIP, 2012. http://dx.doi.org/10.1063/1.4732382.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Robert, Erika V. C., Jessica de Wild, and Phillip J. Dale. "Cu2SnS3-based thin film solar cell from electrodeposition-annealing route." In 2015 IEEE 42nd Photovoltaic Specialists Conference (PVSC). IEEE, 2015. http://dx.doi.org/10.1109/pvsc.2015.7356086.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Acebo, Laura, Ignacio Becerril-Romero, Dioulde Sylla, Yudania Sanchez, Florian Oliva, Victor Izquierdo-Roca, Paul Pistor, and Edgardo Saucedo. "Development of Cu2SnS3 based solar cells by a sequential process." In 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). IEEE, 2016. http://dx.doi.org/10.1109/pvsc.2016.7749619.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!