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Doctors of Sciences

Matanat Ahmad Mehrabova

Mehrabova M.Ə.Place of birth: Azerbaijan, Baku city

Date of birth: 28.04.1964

Education: Baku State University, Physical Department

Scientific degree: Doctor of physics

Title: Associate professor

Topic of PhD thesis:
- specialty code: 01.04.27
- specialty name: Physics of Solid State
- topic name: Interband Faraday rotation in semimagnetic semiconductors and their quantum sized films

Topic of doctoral thesis:
- specialty code: 2225.01; 2220.01
- specialty name: Radiation study of materials; Physics of semiconductors
- topic name: Elektron structure, defect formation energy of chalcogenides АII-IVBVI and effect of ionizing irradiation on their physical properties

Total number of printed scientific publications: 170
- number of scientific publications printed abroad: 92
- number of papers published in journals indexed and abstracted in international databases: 45

Staff training:
- number of PhD: 3

Basic scientific achievements:
      For the first time it has been calculated the electronic structure of the ideal and defective semiconductors Cd(Pb)Te, Cd(Pb)1-xMnxTe and GaS in the framework of DFT by the pseudopotential method, by use of LSDA in the Atomistix ToolKit program, as well as of the semiconductors GaS, GaSe, InSe with anion, cation vacancy or impurity on the base of Green function theory, by the Bond Orbital and LCAO methods. The density of states, total energy, magnetic moments, number of electrons, position of Fermi level, defect formation and threshold energies were defined.
      It has been defined, that defects in investigated semiconductors change the band gap, form local levels in the band gap and valence band, displace Fermi level, as well as form magnetic moments near the defects, ferromagnetic phase change to antiferromagnetic and vice versa in semimagnetic semiconductors.
      It has been established that at compensation of vacancies by the atom of the element in the same subgroup with the same tetrahedral coordination the ionic radius of which is less than the ionic radius of the replaced atom, the local levels formed by defects completely disappear. Using this mechanism it is possible to restore the initial parameters of the crystal. The compensation by the atom of differ coordination and bigger ionic radius, there form addition local levels.
      The effect of γ-irradiation on crystal structure, surface morphology, electrophysical, optical and photoelectric properties of Cd(Pb)1-xMnxTe epitaxial films is studied depending on the sample thickness, Mn atoms concentration and irradiation dose. Epitaxial films were obtained on a mica, glass substrates and BaF2 monocrystalline films in a vacuum (1÷2)10-4Pa by the Molecular Beams Condensation method. It is determined the optimal conditions to obtain of epitaxial films with perfect structure and a clean, smooth surface by using of additional Te source.
      It was determined that at a substrate temperature of Tsub=300 K, the films obtained on glass substrates have polycrystalline and amorphous structure, on mica substrates only polycrystalline structure. At the substrate temperature of Tsub=670К, there were grown epitaxial films with a cubic structure (zinc blende) in the crystalline plane of (111).
      It has been established changes in x-ray diffractometer and AFM spectra after γ-irradiation (E=1.17MeV, E=1.33MeV) of Cd(Pb)1-xMnxTe epitaxial films of dozes ≤25kQr. It is observed that the intensities of some reflexes are reduced in the x-ray spectra, and the particle size reduce in the AFM spectra. Above the 25kGy dose deterioration of surface morphology occurs.
      The significant changes, observed in the VAC and photoconductivity spectra of Cd1-xMnxTe epitaxial films after irradiation by γ-quanta at doses ≤25кGy at Tsub=300K and Pb1-xMnxTe epitaxial films by electron fluxes of Ф≤7·1017см-2 at nitrogen temperature make it possible to create detectors of ionizing irradiation on their basis.
      It has been established that irradiation of epitaxial films change the optical parameters, i.e. the edge of intrinsic absorption is shifted, which affects the band gap. Thus, by changing both the manganese concentration and the irradiation dose, it is possible to control the properties of the samples.
      The possibilities of creating photosensitive heterojunctions based on n-CdTe /р-Cd1-xMnxTe and n-Pb1-xMnxТe/p-PbТe1-yy epitaxial films are determined, which can be used as photoconverters, photodetectors and detectors of ionizing radiation.
      It has been established that in size-quantized Pb1-xMnxTe films, the angle of the interband Faraday rotation (AIFR) increases with increasing of band gap.
      It is determined that AIFR in size-quantized Pb1-xMnxTe films for two specific orientations of crystalline directions with respect to the film surface differ for several orders of magnitude and differ in sign.
      It is shown that in semimagnetic semiconductors Cd1-xMnxTe, AIFR linearly depends on the concentration of paramagnetic ions and a very small amount of manganese ions strongly influences the value of UMPT.

Praktiki təklif:
• Cd(Pb)1-xMnxTe halkogenidlərində Mn konsentrasiyasını dəyişməklə və GaS, GaSe, InSe yarımkeçiricilərinə aşqar vurmaqla zona quruluşunun idarə olunması;
• Cd(Pb)1-xMnxTe yarımleçiricilərinə ionlaşdırırcı radiasiya şüalarının təsiri ilə elektrikkeçiriciliyini, fotokeçiriciliyi, keçiriciliyin tipini, maqnit xassələrini, qadağan olunmuş zonanın enini idarə etmək olur.
• Elektron quruluşu və fotokeçericiliyin xassələrindən istifadə etməklə Cd(Pb)1-xMnxTe epitaksial təbəqələri və onlar əsasında hazırlanmış strukturlardan yüksək həssaslığa malik günəş elementləri, fotodetektorlar, ionlaşdırıcı radiasiya detektorları hazırlamaq mümkündür.

Names of scientific works:
1. Askerov B.M., Ismailov T.H., Mehrabova M.A. Interband Faraday rotation in semimagnetic semiconductors. Physica status solidi (b), 1991, v.163, p.k117-k121.
2. Джахангирли З.А., Мехрабова М.А. Pасчет электронной структуры вакансий в GaSe методом функции Грина. Известия высших учебных заведений, Физика, Томск, 2006, №11, p.8-12.
3. Mehrabova M.A. Calculation of electronic structure of vacancies and their replacements in semiconductors AIIIBVI. Journal “Radioprotection”, vol.43, №5, 2008, p.134.
4. Mehrabova М.А. Detectors in Barrier Structures of Metal-Lamellar Semiconductors. Key Engineering Materials, Trans Tech Publications, Switzerland, 2010, v.464, p.1-10.
5. Меhrаbоvа М.А. Thermodynamic and electronic properties two-dimensional electron gas with heating. «Alternative energetics and ecology», 2010, №6, p.130-135.
6. M.A. Mehrabova, The modeling of calculations of thermodynamic and electronic parameters of hot electrons in a quantum well, International Journal of Energy, NAUN, ISSN: 1998-4316, issue 4, vol. 4, 2010, p.63-70.
7. M.A. Mehrabova, R.S. Madatov. Calculation of the electron structure of vacancies and their compensated states in III-VI semiconductors. Semiconductors, Russian, vol.45, №8, 2011, p.998-1005.
8. Madatov R.S., Najafov A.I., Tagiyev T.B., Mekhrabova M.A., Gazanfarov M.P. The impact of ionizing radiation on the mechanism of current transition in TlInSe2 monocrystals. Physics of solid state. 2011, v.45, №11, р. 2097-2101.
9. M.A. Mehrabova, Г.А. Абиев, Ш.А. Топчиева, Э.Т. Бабаев. Определение радионуклидов в составе змеиного яда и возможности создания детекторов на их основе. Вестник МГОУ. Серия «Естественные науки», №3/2011, стр.7-11, Россия, Москва.
10. M.A. Mehrabova, I.R. Nuriyev, H.S. Orujov. Electron Structure and Optical Properties of Cd1-xMnxTe Thin Films. International Journal of Materials, 2014, v.1, p.63-70.
11. M.A. Mehrabova, H.R. Nuriyev, H.S. Orujov, A.M. Nazarov, R.M. Sadigov, V.N. Poladova, Defect formation energy for charge states and electrophysical properties of CdMnTe, Invited paper, Proc. SPIE Photonics, Devices and Systems VI, vol.9450, 2015, p.94500Q-1-10.
12. M.A. Mehrabova, H.S. Orujov, N.H. Hasanov, Ab initio study of defects in CdMnTe: Electronic structure and related properties, SciencePG International Journal of Materials Science and Applications, 2014, 3(6-1), p.24-32.
13. M.A. Mehrabova, H.R. Nuriyev, T.B. Taghiyev, R.M. Sadigov, A.M. Nazarov, N.I. Huseynov, Impact of γ-irradition on srtucture and electrophysical properties of CdMnTe, SciencePG International Journal of Materials Science and Applications, 2014, 3(6-1), p.20-23.
14. И.Р.Нуриев, А.М.Назаров, M.A.Mehrabova, Р.М.Садыгов, Особенности роста, структура и морфология поверхности эпитаксиальных пленок Cd1-xMnxTe, Журнал «Неорганические Материалы», 2016, т.52, №9, с.1-4.
15. И.Р. Нуриев, М.А. Мехрабова, А.М. Назаров, Р.М. Садыгов, Н.Г. Гасанов. Рост, cтруктура и морфология поверхности эпитаксиальных пленок CdTe. ФТП, v.51, №1, p. 36-39, 2017.
16. И.Р. Нуриев, М.А. Мехрабова. Н.Г. Гасанов. Cтруктура и морфология поверхности эпитаксиальных пленок Cd1-xMnxSe. Поверхность, 2018, № 5, с. 98–101.

Membership with international and foreign scientific organizations:
1. Academician of International Academy of Ecology and Life Protection Sciences
2. Professor of International Ecoenergy Academy
3. Chief Technology Commercialization Officer
4. Expert of the journal “Physica B: Physics and Condensed Matter”
5. Member of org. committee of the International Conference Photonics-2017 ”, Prague, Czech Republic
6. Member of the International Scientific Committee of the III International Conference "Security Management and Society", Brno, Czech Republic, 2012
7. Chief editor of the special issue of the journal “Material science” USA, Science Publishing Group”, 2014,
8. Editorial Member of 3 USA International Journals of “Science Publishing Group”:
1) American Journal of Physics and Applications,
2) American Journal of Nanoscience and Nanotechnology,
3) International Journal of Materials Science and Applications

Pedagogical activity: Baku State University, “Lyceum of Young Talents”

Other activities:
- Preparation for international and republic competitions of lyceum students. 15 winners.
- Technology Commercialization

Awards and prizes:
1. Diploma of Young scientists of XXI century
2. Honorable diploma of Lyceum of Young Talents of Baku State university

Main place of work and its address:
Institute of Radiation Problem of ANAS, B.Vahabzadeh street, 9

Position: Leading scientist

Office phone: (+994 12) 5383224 (132)
Mobile: (+994 50) 7318177
Home: (+994 12) 4325187