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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">mateltech</journal-id><journal-title-group><journal-title xml:lang="ru">Известия высших учебных заведений. Материалы электронной техники</journal-title><trans-title-group xml:lang="en"><trans-title>Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1609-3577</issn><issn pub-type="epub">2413-6387</issn><publisher><publisher-name>MISIS</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.17073/1609-3577-2022-2-107-114</article-id><article-id custom-type="elpub" pub-id-type="custom">mateltech-481</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>Материаловедение и технология. Полупроводники</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATERIALS SCIENCE AND TECHNOLOGY. SEMICONDUCTORS</subject></subj-group></article-categories><title-group><article-title>Определение  отклонения от стехиометрии в  широкозонных полупроводниковых соединений АIIВVI по составу равновесной паровой фазы</article-title><trans-title-group xml:lang="en"><trans-title>Determination of stoichiometry deviation in wide-band II-VI semiconductors on the basis of equilibrium vapor phase composition</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-0879-7013</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кобелева</surname><given-names>С. П.</given-names></name><name name-style="western" xml:lang="en"><surname>Kobeleva</surname><given-names>S. P.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Ленинский просп., д. 4, стр. 1, Москва, 119049</p><p>Кобелева Светлана Петровна — кандидат физ.−мат. наук, старший научный сотрудник, доцент кафедры «ППЭ и ФПП»</p></bio><bio xml:lang="en"><p>4-1 Leninsky Ave., Moscow 119049</p><p>Svetlana P. Kobeleva — Cand. Sci. (Phys.-Math.), Senior Researcher, Associate Professor </p></bio><email xlink:type="simple">kob@misis.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Национальный исследовательский технологический университет «МИСиС»</institution><country>Россия</country></aff><aff xml:lang="en"><institution>National University of Science and Technology MISiS</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2022</year></pub-date><pub-date pub-type="epub"><day>21</day><month>07</month><year>2022</year></pub-date><volume>25</volume><issue>2</issue><fpage>107</fpage><lpage>114</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Кобелева С.П., 2022</copyright-statement><copyright-year>2022</copyright-year><copyright-holder xml:lang="ru">Кобелева С.П.</copyright-holder><copyright-holder xml:lang="en">Kobeleva S.P.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://met.misis.ru/jour/article/view/481">https://met.misis.ru/jour/article/view/481</self-uri><abstract><p>Предложен метод определения отклонения от стехиометрии в халькогенидах кадмия и цинка, основанный на анализе температурной зависимости отношения парциальных давлений компонентов при испарении твердого соединения в ограниченный объем, что отличает его от методов сбора избыточного компонента при испарении в большие объемы. Метод основан на измерении парциальных давлений компонентов паровой фазы при нагреве материала до температур выше 800 К и на последующем решении системы уравнений материального баланса и уравнения электронейтральности для расчета исходного отклонения от стехиометрии в соединении при комнатной температуре. Концентрации собственных точечных дефектов рассчитывают методом квазихимических реакций. Независимыми переменными в системе уравнений являются искомое отклонение от стехиометрии, парциальное давление металла и концентрация свободных электронов. Показано, что в уравнении материального баланса параметр, определяющий чувствительность метода по отклонению от стехиометрии — отношение объемов паровой и твердой фаз, можно считать постоянным при нагреве и испарении, если он не превышает 50. Если парциальные давления измерять по оптической плотности паров, чувствительность метода может быть не хуже 10-6 % (ат.).</p></abstract><trans-abstract xml:lang="en"><p>A method of determining stoichiometry deviation in cadmium and zinc chalcogenides that is based on the temperature dependence of the ratio of components partial pressures during evaporation of solid compounds in a limited volume has been suggested. The new method differs from methods implying the collection of excessive component during evaporation in large volumes. The method includes measuring vapor phase components partial pressures during material heating to above 800 K, solving a set of material balance equations and the electric neutrality equation, and calculating the stoichiometry deviation in the initial compound at room temperature. Intrinsic point defect concentrations are calculated using the method of quasichemical reactions. The independent variables in the set of equations are the sought stoichiometry deviation, the partial pressure of the metal and the concentration of free electrons. We show that the parameter of the material balance equation which determines the method’s sensitivity to stoichiometry deviation, i.e., the volume ratio of vapor and solid phases, can be considered constant during heating and evaporation unless this parameter exceeds 50. If the partial pressure is measured based on the optical density of the vapors, then the sensitivity of the method can be increased to not worse than 10-6 at.%.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>отклонение от стехиометрии</kwd><kwd>широкозонные полупроводники</kwd><kwd>халькогениды кадмия и цинка</kwd><kwd>парциальное давление</kwd></kwd-group><kwd-group xml:lang="en"><kwd>stoichiometry deviation</kwd><kwd>wide-band semiconductors</kwd><kwd>cadmium and zinc chalcogenides</kwd><kwd>partial pressure</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Isshiki M., Wang J. II-IV semiconductors for optoelectronics: CdS, CdSe, CdTe. In: Kasap S., Capper P. (eds.) Springer handbook of electronic and photonic materials. Cham, Switzerland: Springer; 2017: 853—865. https://doi.org/10.1007/978-3-319-48933-9_33</mixed-citation><mixed-citation xml:lang="en">Kasap S., Capper P., eds. Isshiki M., Wang J. II-IV semiconductors for optoelectronics: CdS, CdSe, CdTe. In: Springer handbook of electronic and photonic materials. Cham, Switzerland: Springer; 2017: 853—865. https://doi.org/10.1007/978-3-319-48933-9_33</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Triboulet R., Siffert P. CdTe and related compounds; physics, defects, hetero- and nano-structures, crystal growth, surfaces and applications. Elsevier; 2010. 296 p. https://doi.org/10.1016/C2009-0-17817-0</mixed-citation><mixed-citation xml:lang="en">Triboulet R., Siffert P. CdTe and related compounds; physics, defects, hetero- and nano-structures, crystal growth, surfaces and applications. Elsevier; 2010. 296 p. https://doi.org/10.1016/C2009-0-17817-0</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Tinedert I.E., Pezzimenti F., Megherbi M.L., Tumer T.O. Tumer O.T., Finger M.H., Gordon E.E., Ramsey B.D., Rhiger D.R., Sharma D.P. Test results of preliminary CdZnTe pixel detectors for possible application to HXT on the Constellation-X mission. Proceedings of SPIE. X-ray and Gamma-ray instrumentation for Astronomy XIII. 2004; 5165: 548—554. https://doi.org/10.1117/12.515619</mixed-citation><mixed-citation xml:lang="en">Tumer O.T., Finger M.H., Gordon E.E., Ramsey B.D., Rhiger D.R., Sharma D.P. Test results of preliminary CdZnTe pixel detectors for possible application to HXT on the Constellation-X mission. Proceedings of SPIE. X-ray and Gamma-ray instrumentation for Astronomy XIII. 2004; 5165: 548—554. https://doi.org/10.1117/12.515619</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Del Sordo S., Abbene L., Caroli E., Mancini A.M., Zappettini A., Ubertini P. Progress in the development of CdTe and CdZnTe semiconductor radiation detectors for astrophysical and medical applications. Sensors. 2009; 9(5): 3491—3526. https://doi.org/10.3390/s90503491</mixed-citation><mixed-citation xml:lang="en">Del Sordo S., Abbene L., Caroli E., Mancini A.M., Zappettini A., Ubertini P. Progress in the development of CdTe and CdZnTe semiconductor radiation detectors for astrophysical and medical applications. Sensors. 2009; 9(5): 3491—3526. https://doi.org/10.3390/s90503491</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Дворянкин В.Ф., Дворянкина Г.Г., Иванов Ю.М., Кудряшов А.А., Петров А.Г. Фотовольтаические детекторы рентгеновского излучения на основе кристаллов CdTe с p-n-переходом. Журнал технической физики. 2010; 80(7): 156—158.</mixed-citation><mixed-citation xml:lang="en">Dvoryankin V.F., Dvoryankina G.G., Ivanov Yu.M., Kudryashov A.A., Petrov A.G. Photovoltaic X-ray detectors based on CdTe crystals with p-n junction. Zhurnal Tekhnicheskoi Fiziki. 2010; 80(7): 156—158. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Tinedert I.E., Pezzimenti F., Megherbi M.L., Saadoune A. Design and simulation of a high efficiency CdS/CdTe solar cell. Optik. 2020; 208: 164112. https://doi.org/10.1016/j.ijleo.2019.164112</mixed-citation><mixed-citation xml:lang="en">Tinedert I.E., Pezzimenti F., Megherbi M.L., Saadoune A. Design and simulation of a high efficiency CdS/CdTe solar cell. Optik. 2020; 208: 164112. https://doi.org/10.1016/j.ijleo.2019.164112</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Bosio A., Rosa G., Romeo N. Past, present and future of the thin film CdTe/CdS solar cells. Solar Energy. 2018; 175: 31—43. https://doi.org/10.1016/j.solener.2018.01.018</mixed-citation><mixed-citation xml:lang="en">Bosio A., Rosa G., Romeo N. Past, present and future of the thin film CdTe/CdS solar cells. Solar Energy. 2018; 175: 31—43. https://doi.org/10.1016/j.solener.2018.01.018</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Baines T., Shalvey T.P., Major J.D. Pt 10. CdTe solar cells. In: A Comprehensive guide to solar energy systems. Elsevier; 2018: 215—232. https://doi.org/10.1016/B978-0-12-811479-7.00010-5</mixed-citation><mixed-citation xml:lang="en">Baines T., Shalvey T.P., Major J.D. Pt 10. CdTe solar cells. In: A comprehensive guide to solar energy systems. Elsevier; 2018: 215—232. https://doi.org/10.1016/B978-0-12-811479-7.00010-5</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Scheiber C., Giakos G.C. Medical applications of CdTe and CdZnTe detectors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2001; 458(1–2): 12—25. https://doi.org/10.1016/S0168-9002(00)01032-9</mixed-citation><mixed-citation xml:lang="en">Scheiber C., Giakos G.C. Medical applications of CdTe and CdZnTe detectors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2001; 458(1–2): 12—25. https://doi.org/ 10.1016/S0168-9002(00)01032-9</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Kroger F.A. The chemistry of imperfect crystals. Amsterdam: North-Holland; 1964. 1039 p.</mixed-citation><mixed-citation xml:lang="en">Kroger F.A. The chemistry of imperfect crystals. Amsterdam: North-Holland; 1964. 1039 p.</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Ivanov Y.M. Configuration of the cadmium telluride homogeneity boundaries. Russian Journal of Inorganic Chemistry. 2014; 59(14): 1705—1714. https://doi.org/10.1134/S0036023614140034</mixed-citation><mixed-citation xml:lang="en">Ivanov Y.M. Configuration of the cadmium telluride homogeneity boundaries. Russian Journal of Inorganic Chemistry. 2014; 59(14): 1705—1714. https://doi.org/10.1134/S0036023614140034</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Avetisov I. Mozhevitina E., Khomyakov A., Avetisov R. Nonstoichiometry of AIIBVI semiconductors. Crystal Research and Technology. 2015; 50(1): 115—123. https://doi.org/10.1002/crat.201400215</mixed-citation><mixed-citation xml:lang="en">Avetisov I. Mozhevitina E., Khomyakov A., Avetisov R. Nonstoichiometry of AIIBVI semiconductors. Crystal Research and Technology. 2015; 50(1): 115—123. https://doi.org/10.1002/crat.201400215</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Avetisov I., Mozhevitina E., Khomyakov A., Khanh T. Universal approach for nonstoichiometry determination in binary chemical compounds. Crystall Reserch Technology. 2015; 50(1): 93—100. https://doi.org/10.1002/crat.201400201</mixed-citation><mixed-citation xml:lang="en">Avetisov I. Mozhevitina E., Khomyakov A., Khanh T. Universal approach for nonstoichiometry determination in binary chemical compounds. Crystall Reserch Technology. 2015; 50(1): 93—100. https://doi.org/10.1002/crat.201400201</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Иванов Ю.М., Яковлева В.Т., Андрейчук А.Н., Морозова Л.П. Метод концентрирования избыточного компонента для определения его концентрации в нестехиометрических соединениях. Известия АН СССР. Неорганические материалы. 1977; (6): 1082.</mixed-citation><mixed-citation xml:lang="en">Ivanov Yu.M., Yakovleva V.T., Andreychuk A.N., Morozova L.P. The method of concentration of the excess component to determine its concentration in non-stoichiometric compounds. Izvestiya AN SSSR. Neorganicheskie Materialy. 1977; (6): 1082.</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Зломанов В.П., Аветисов И.Х., Можевитина Е.Н. Физическая химия твердого тела. Р-Т-х диаграммы фазовых равновесий. М.: РХТУ им. Д. И. Менделеева; 2019. 184 с.</mixed-citation><mixed-citation xml:lang="en">Zlomanov V.P., Avetisov I.H., Mozhevitina E.N. Physical chemistry of a solid. P-T-x diagrams of phase equilibria. Мoscow: RKhTU im. D.I. Mendeleeva; 2019. 184 p. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Аветисов И.Х. Фазовые равновесия в системах А(II)В(VI). В сб.: Высокочистые вещества. М.: Научный мир; 2018: 704—753.</mixed-citation><mixed-citation xml:lang="en">Avetisov I.H. Phase equilibria in systems А(II)В(VI). In: High-purity substances. Moscow: Nauchnyi mir; 2018: 704—753. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Rudolph P. Fundamental studies on Bridgman growth of CdTe. Progress in Crystal Growth and Characterization of Materials. 1994; 29(1–4): 275—381. https://doi.org/10.1016/0960-8974(94)90009-4</mixed-citation><mixed-citation xml:lang="en">Rudolph P. Fundamental studies on Bridgman growth of CdTe. Progress in Crystal Growth and Characterization of Materials. 1994; 29(1–4): 275—381. https://doi.org/10.1016/0960-8974(94)90009-4</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Yellin N., Szapiro Y. Calculation of the partial vapor pressures of tellurium and cadmium over non-stoichiometric CdTe in the temperature range 750—1050 °C. Journal of Crystal Growth. 1985; 73(1): 77—82. https://doi.org/10.1016/0022-0248(85)90333-1</mixed-citation><mixed-citation xml:lang="en">Yellin N., Szapiro Y. Calculation of the partial vapor pressures of tellurium and cadmium over non-stoichiometric CdTe in the temperature range 750—1050 °C. Journal of Crystal Growth. 1985; 73(1): 77—82. https://doi.org/10.1016/0022-0248(85)90333-1</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Шалимова К.В. Физика полупроводников. СПб.: Лань; 2010. 400 с.</mixed-citation><mixed-citation xml:lang="en">Shalimova K.V. Physics of semiconductors. St. Petersburg: Lan’; 2010. 392 p. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Kröger F.A. The defect structure of CdTe. Revue de Physique Appliquee. 1977; 12(2): 205—210. https://doi.org/10.1051/rphysap:01977001202020500</mixed-citation><mixed-citation xml:lang="en">Kröger F.A. The defect structure of CdTe. Revue de Physique Appliquee. 1977; 12(2): 205—210. https://doi.org/10.1051/rphysap:01977001202020500</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Медведев С.А., Максимовский С.Н., Киселева К.В., Клевков Ю.В., Сентюрина Н.Н. О природе точечных дефектов в нелегированном CdTe. Известия АН СССР. Неорганические материалы. 1973; 9(3): 356—360.</mixed-citation><mixed-citation xml:lang="en">Medvedev S.A., Maksimovsky S.N., Kiseleva K.V., Klevkov Yu.V., Sentyurina N.N. On the nature of point defects in undoped CdTe. Izvestiya AN SSSR. Neorganicheskie Materialy. 1973; 9(3): 356—360. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit22"><label>22</label><citation-alternatives><mixed-citation xml:lang="ru">Медведев С.А., Мартынов В.Н, Кобелева С.П. О возможности существования антиструктурных дефектов в нелегированном CdTe. Известия АН СССР. Кристаллография. 1983; 28(2): 394.</mixed-citation><mixed-citation xml:lang="en">Medvedev S.A., Martynov V.N., Kobeleva S.P. On the possibility of existence of anti-structural defects in undoped CdTe. Izvestiya AN SSSR. Kristallografiya. 1983; 28(2): 394. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit23"><label>23</label><citation-alternatives><mixed-citation xml:lang="ru">Fochuk P., Grill R., Panchuk O. The nature of point defects in CdTe. Journal of Electronic Materials. 2006; 35(6): 1354—1359. https://doi.org/10.1007/s11664-006-0268-9</mixed-citation><mixed-citation xml:lang="en">Fochuk P., Grill R., Panchuk O. The nature of point defects in CdTe. Journal of Electronic Materials. 2006; 35(6): 1354—1359. https://doi.org/10.1007/s11664-006-0268-9</mixed-citation></citation-alternatives></ref><ref id="cit24"><label>24</label><citation-alternatives><mixed-citation xml:lang="ru">Вerding М.А. Native defects in CdTe. Physical Review B. 1999; 60(12): 8943—8950. https://doi.org/10.1103/PhysRevB.60.8943</mixed-citation><mixed-citation xml:lang="en">Вerding М.А. Native defects in CdTe. Physical Review B. 1999; 60(12): 8943—8950. https://doi.org/10.1103/PhysRevB.60.8943</mixed-citation></citation-alternatives></ref><ref id="cit25"><label>25</label><citation-alternatives><mixed-citation xml:lang="ru">Kosyak V.V., Opanasyak A.S., Protsenko I.Yu. Ensemble of point defects in CdTe single crystals and films in the case of full equilibrium and quenching. Functional Materials. 2005; 12(4): 797—806.</mixed-citation><mixed-citation xml:lang="en">Kosyak V.V., Opanasyak A.S., Protsenko I.Yu. Ensemble of point defects in CdTe single crystals and films in the case of full equilibrium and quenching. Functional Materials. 2005; 12(4): 797—806.</mixed-citation></citation-alternatives></ref><ref id="cit26"><label>26</label><citation-alternatives><mixed-citation xml:lang="ru">Brebric R.F., Strauss A.J. Partial pressures in equilibrium with group IV tellurides. I. Optical absorption method and results for PbTe. Journal of Chemical Physics. 1964; 40: 3230—3235. https://doi.org/10.1063/1.1724990</mixed-citation><mixed-citation xml:lang="en">Brebric R.F., Strauss A.J. Partial pressures in equilibrium with group IV Tellurides. I. Optical absorption method and results for PbTe. Journal of Chemical Physics. 1964; 40: 3230—3235. https://doi.org/10.1063/1.1724990</mixed-citation></citation-alternatives></ref><ref id="cit27"><label>27</label><citation-alternatives><mixed-citation xml:lang="ru">Медведев С.А., Мартынов В.Н., Кобелева С.П. Исследование температурной зависимости парциальных давлений компонентов над теллуридом кадмия. Электронная техника. Серия 6. Материалы. 1980; (8(145)): 53—58.</mixed-citation><mixed-citation xml:lang="en">Medvedev S.A., Martynov V.N., Kobeleva S.P. Investigation of temperature dependence of partial pressures of components over cadmium telluride. Elektronnaya Tekhnika. Seriya 6. Materialy. 1980; (8(145)): 53—58. (In Russ.)</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
