Теоретические исследования баллистического и поверхностного фотогальванического эффекта и двумерных электронных состояний в полупроводниках кубической симметрии

Аннотация

OF DISSERTATION OF THE DOCTOR OF PHILOSOPHY (PhD) ON PHYSICAL AND MATHEMATICAL SCIENCES Andijan – 2018 35 The theme of dissertation of doctor of philosophy (PhD) on physical and mathematical sciences was registered at the Supreme Attestation Commission of the Cabinet of Ministers of the Republic of Uzbekistan under No. В2017.2.PhD/FM83. Dissertation has been prepared at Fergana state university. The abstract of the dissertation is posted in three languages (uzbek, russian, english (resume)) on the website of scientific council (www.adu.uz) and on the «Ziyonet» Information and educational portal (www.ziyonet.uz). Scientific supervisor: Karimov Ibroxim Nabiyevich Doctor of Physical and Mathematical Sciences Official opponents: Imamov Erkin Zunnunovich Doctor of Physical and Mathematical Sciences, professor Gulyamov Gafur Doctor of Physical and Mathematical Sciences, professor Leading organization: National university of Uzbekistan. Defense will take place «____» _____________2018 at _____ at the meeting of Scientific Council number PhD.28.02.2018.FM.60.01 at Andijan state university. (Address: 170100, Uzbekistan, Andijan, 129 Universitet street. Phone/fax: 0(374) 223-88-30, e-mail: agsu_info@edu.uz.) Dissertation is possible to review in Information-resource centre at Andijan state university (is registered under No.____) Address: 170100, Uzbekistan, Andijan, 129 Universitet street. Phone/fax: 0(374) 223-88-30, e-mail: agsu_info@edu.uz. Abstract of dissertation sent out on «____» _______________2018 S.Z. Zaynabidinov Chairman of scientific council on award of scientific degree, DSc in physics and mathematics, academician A.O. Kurbanov Scientific secretary of scientific council on award of scientific degree, PhD in physics and mathematics M.Z. Nosirov Vice- chairman of scientific Seminar under Scientific Council on award of scientific degree, PhD in physics and mathematics, doсent 36 INTRODUCTION (abstract of PhD dissertation) The aim of research work is a theoretical investigation of the mechanisms of the surface and linear photovoltaic effect in semiconductors with cubic symmetry, also two-dimensional electronic states. The objects of research work are asymmetric multilayer semiconductor structures consisting of alternating potential barriers and wells, and bulk p-GaAs semiconductors. Scientific novelty of dissertation work consists in the following: the oscillation of the transmission coefficient was determined when the effective masses of electrons in the neighboring layers of an asymmetric layered structure are different on the basis of the Bastard condition; a mathematical expression was determined for the temperature dependence of the current of the linear photovoltaic effect in p-GaAs observed in intersubband single-photon transitions due to the asymmetry of electron-phonon and electron- photon interactions; an asymmetric scattering of electrons by photons and phonons in semiconductors with a complex valence band was calculated by the Keldysh diagram technique, it was shown that the spectral dependence of the ballistic photocurrent is determined by the spectral dependence of the absorption coefficient; it was shown that the appearance of a ballistic photocurrent is due to the change in the numerical value of the photocurrent, depending on the sign of the band parameters of the semiconductor, taking into account the linear and cubic terms depending to the wave vector in the Hamiltonian of holes; a mathematical expression for the surface photocurrent in a semi-infinite multivalley semiconductor in an external magnetic field was determined, depending on temperature and frequency. Implementation of the research results: Based on the results of the research of the ballistic and surface photovoltaic effect and two-dimensional electron states in semiconductors of cubic symmetry: the results of researches of photovoltaic effects were used in the grant «Nonlinear and dispersion effects in semiconductors» in the study of dispersion optical phenomena (Reference No. 11217-278/211.5 of the Physical-technical Institute named after A.F. Ioffe of the Russian Academy of Sciences from March 15, 2018) . The use of scientific results maked it possible to study theoretically nonlinear intensities of photon-kinetic phenomena in bulk semiconductors. temperature dependence of the surface photocurrent in a semi-infinite multivalley semiconductor was used in the grant No. 10/2000 «Exciton-polariton luminescence of semiconductor crystals and quantum-size structures during photoexcitation and channeling of ions» in explaining the mechanisms of optical phenomena in dimensionally quantized semiconductors. (Reference No. FTA-02- 11/834 of Agency of Science and Technology from October 10, 2017). The use of scientific results maked it possible to study the effect of surface phenomena on exciton-polariton optical transitions; 37 the results of the research of electronic states in multilayer semiconductor structures with allowance for t