Analyzing the Change in the Composition of a CdTe Surface upon Implanting Ions and Subsequent Annealing A. A. Abduvayitov, Kh. Kh. Boltaev, B. E. Umirzakov, D. A. Tashmukhamedova, G. Abdurakhmanov Bulletin of the Russian Academy of Sciences Physics, 2024 A CdTeO3 film is obtained by implanting $${\text{O}}_{2}^{ + }$$ ions into a single-crystal CdTe/Mo(111) film and annealing for 30 min at Т = 800 K. It is established that the valence band of the CdTeO3 film reveals three maxima caused by the excitation of electrons from the 5s electrons of Cd, the 2p electrons of O, and the hybridized levels of 5s Cd + 2p O. Cd–Te–O compounds form in the near-surface layer during the implantation of $${\text{O}}_{2}^{ + }$$ ions with E0 ≥ 10 keV, producing a three-layer CdTe/CdTeO/CdTe nanosystem.
ANALYSIS OF THE CHANGE IN THE COMPOSITION OF THE CdTe SURFACE UPON IMPLANTATION OF (Formula present) IONS AND SUBSEQUENT ANNEALING A.A. Abduvaitov, , G.T. Imanova, and Advanced Physical Research, 2024 The methods of implantation of О_2^+ ions into a single-crystal CdTe/Mo(111) film followed by annealing at Т=800 K for 30 min resulted in the obtained CdTeO3 film. Ion implantation, heating, and investigation of the composition, density of state of valence electrons, and parameters of energy bands are carried out in the same ultra-high vacuum device (10-7 Pa). The surface morphology and crystal structure of the oxide are studied using standard scanning electron microscopy and high-speed electron diffraction setups. It has been established that in the valence band of the CdTeO3 film there is a 3rd maximum due to the excitation of electrons from 5s Cd electrons and 2p O electrons and bending 5s Cd + 2pO electrons. Based on the Eg data, it is concluded that quantum size effects are not detected in the case of CdTeO3 films with a thickness of ≥ 30 Å.
The influence of implantation of Mg+ ions and subsequent annealing on the composition, electronic structures, emission and optical properties of CdF2 Akbarjon Аbduvayitov, Gunel Imanova, Dilnoza Tashmukhamedova, Khurshid Boltaev, Boltakhodja Umirzakov Scientific Herald of Uzhhorod University Series Physics, 2023 Relevance. In the case of bombardment with Mg metal ions, the changes are accompanied by the introduction of metal atoms and the formation of various types of compounds. Thus, CdF2 is intensively decomposed into components in the near-surface layer in the process of ion implantation. A small part of these components can be sprayed from the surface. Due to the high chemical activity, almost all of the liberated fluorine atoms again enter into a chemical bond with both the atoms of the alloying element and the atoms of cadmium. Consequently, three-component compounds are formed in the near-surface layer. Therefore, it is necessary to define the electronic states, band energy, and optical parameters of CdF2 and Cd0.6Mg0.4F2 films. Purpose. The composition, structure, and properties of CdF2 implanted with Mg+ ions in combination with thermal and laser annealing for the first time were the research aims. Methodology. The experimental studies were carried out at a vacuum of at least 10-7 Pa using the methods of Auger electron spectroscopy (AES) and ultraviolet photoelectron spectroscopy (UVES). The depth distribution profiles of atoms were determined by the AES method in combination with layer-by-layer etching of the surface with Ar+ ions with E0=2-3 keV. Results. CdF2 is intensively decomposed into components in the near-surface layer in the process of ion implantation. Consequently, three-component compounds are formed in the near-surface layer. Band-energy parameters and densities of the state of electrons in the valence band of this film are determined. Conclusions. The effect of the implantation of Mg+ ions on the composition and electronic structure of single-crystal CdF2/Si(III) films was studied for the first time. The densities of electronic states, band-energy and optical parameters of CdF2 and Cd0.6Mg0.4F2 films have been determined
Study of the Composition of Uncontrolled Impurities and the Profiles of Their Distribution at the Ni–CdS Interface A. A. Abduvayitov, Kh. Kh. Boltaev, G. A. Rozikov Journal of Surface Investigation, 2022 The atomic concentration of uncontrolled impurities, their chemical composition on the surface of Ni films, as well as the distribution profiles of atoms of some impurities in Ni films and at the interface of the Ni–CdS system are investigated using Auger-electron spectroscopy and secondary-ion mass spectrometry. Ni films with a thickness of 0.5–1 μm are obtained by thermal evaporation in vacuum (~10–6 Pa). In a well degassed Ni film, in addition to oxygen and carbon, impurity atoms of more than 10 elements are found, but their total concentration is only ~1–1.5 at %. These impurity atoms penetrate the Ni–CdS interface and their penetration depth into the Ni layer is 0.3–0.4 µm. At the interface of the Ni–CdS system, the oxygen concentration reaches 8–10 at %, resulting in the formation of NiO- and NiO2-type compounds.
Composition and Structure of Ga1 – xNaxAs Nanolayers Produced near the GaAs Surface by Na+ Implantation Kh. Kh. Boltaev, Zh. Sh. Sodikjanov, D. A. Tashmukhamedova, B. E. Umirzakov Technical Physics, 2017 The composition and structure of nanodimensional Ga1 – xNa x As phases produced by implantation of Na+ ions into the near-surface area of GaAs have been studied by Auger electron spectroscopy and fast electron diffraction. It has been found that the thickness of the ternary epitaxial layer is 10–12 nm for ion energy E0 = 20 keV. The composition of the three-layer nanosystems is GaAs–Ga0.5Na0.5As–GaAs.
Composition of uncontrolled impurities and their chemical states and depth profiles at the Al-Si interface A. A. Abduvaiitov, Kh. Kh. Boltaev Technical Physics, 2015 Auger electron spectroscopy and secondary-ion mass spectrometry are used to study the compositions of uncontrolled impurity atoms, their chemical composition, and the atomic distribution profiles at the Al-Si interface. Low concentrations (<0.1%) of impurity C, O, N, Ti, Fe, and other atoms are detected in Al. An analysis of the chemical shifts of the Auger peaks of metal atoms shows that compounds of the AlO and Al2O3 types form at the Al-Si interface.
Influence of ion bombardment on the profile of the depth distribution of impurity atoms in Si used for solar cells and diode structures B. E. Umirzakov, S. J. Nimatov, H. H. Boltaev Journal of Surface Investigation, 2014 The chemical composition of the surfaces and surface layers of Si samples used in solar cells are studied using Auger electron spectroscopy (AES). It is shown that the low-energy implantation of Ba and O ions leads to the redistribution of impurity atoms in the surface layer and can prevent impurity atoms adsorbed onto the surface from penetrating inside the sample.
Structure and electronic properties of nanoscale phases and nanofilms of metal silicides produced by ion implantation in combination with annealing Kh. Kh. Boltaev, D. A. Tashmukhamedova, B. E. Umirzakov Journal of Surface Investigation, 2014 It is established that ion implantation in combination with annealing makes it possible to produce regularly arranged nanocrystalline phases and continuous films of metal silicides in the surface region of Si. It is shown that silicide nanocrystals and nanofilms crystallize in the cubic lattice. A model of a Si surface with silicide nanocrystals is developed.
