scholarly journals Дисперсия плазменных колебаний в аморфных халькогенидных полупроводниках

2021 ◽  
Vol 91 (6) ◽  
pp. 1057
Author(s):  
В.М. Стожаров
Keyword(s):  
Thin Films ◽  
Silicon Crystal ◽  
Molybdenum Sulfide ◽  
Dispersion Curves ◽  
Amorphous Semiconductor ◽  
Mechanical Stresses ◽  
Semiconductor Film ◽  
Total External Reflection ◽  
X Rays ◽  
Chalcogenide Semiconductors

Thin films of amorphous chalcogenide semiconductors on a silicon crystal are studied by the method of plasma vibration dispersion and the asymmetry of the number of electrons in the zone of formation of the total external reflection of X-rays and the excitation of plasmons is calculated. Loop-like dispersion curves were observed and the average plasmon energies and the associated internal mechanical stresses and polarization of the studied films were determined. The absence of internal mechanical stresses and polarization in an amorphous semiconductor film of molybdenum sulfide is found.

scholarly journals Rubbing induced reversible fluorescence switching in thiophene derivate organic semiconductor film by mechanical amorphisation

2021 ◽  
Author(s):  
Massimiliano Cavallini ◽  
Ilse Manet ◽  
Marco Brucale ◽  
Laura Favaretto ◽  
Manuela Melucci ◽  
...  
Keyword(s):  
Thin Films ◽  
Organic Semiconductor ◽  
Semiconductor Film ◽  
Semiconductor Thin Films ◽  
Fluorescence Switching ◽  
Polymorphic Nature

Here, we applied rubbing on thiophene derivate organic semiconductor thin films to induce a reversible mechanical amorphisation. Amorphisation is associated with fluorescence switching, which is regulated by the polymorphic nature...

How to Use the Features of Total Reflection of X-Rays for Energy Dispersive XRF

1988 ◽  
Vol 32 ◽  
pp. 105-114 ◽  
Author(s):  
H. Schwenke ◽  
W. Berneike ◽  
J. Knoth ◽  
U. Weisbrod
Keyword(s):  
Thin Films ◽  
Penetration Depth ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
X Rays ◽  
X Ray ◽  
Characteristic Features ◽  
Respective Characteristic ◽  
Nanometer Regime ◽  
Sensitive Method

AbstractThe total reflection of X-rays is mainly determined by three parameters , that is the orltical angle, the reflectivity and the penetration depth. For X-ray fluorescence analysis the respective characteristic features can be exploited in two rather different fields of application. In the analysis of trace elements in samples placed as thin films on optical flats, detection limits as low as 2 pg or 0.05 ppb, respectively, have been obtained. In addition, a penetration depth in the nanometer regime renders Total Reflection XRF an inherently sensitive method for the elemental analysis of surfaces. This paper outlines the main physical and constructional parameters for instrumental design and quantitation in both branches of TXRF.

Investigation of the phase shift in X-ray forward diffraction using an X-ray interferometer

1998 ◽  
Vol 5 (3) ◽  
pp. 967-968 ◽  
Author(s):  
Keiichi Hirano ◽  
Atsushi Momose
Keyword(s):  
Phase Shift ◽  
Silicon Crystal ◽  
Dynamical Theory ◽  
Perfect Crystal ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bragg Geometry

The phase shift of forward-diffracted X-rays by a perfect crystal is discussed on the basis of the dynamical theory of X-ray diffraction. By means of a triple Laue-case X-ray interferometer, the phase shift of forward-diffracted X-rays by a silicon crystal in the Bragg geometry was investigated.

Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

2022 ◽  
Vol 43 (1) ◽  
pp. 012801
Author(s):  
R. Rahaman ◽  
M. Sharmin ◽  
J. Podder
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Spray Pyrolysis Technique ◽  
Band Gap Energy ◽  
Dielectric Constants ◽  
X Rays ◽  
Electron Effective Mass ◽  
Mn Doping ◽  
Type Transition ◽  
Mn Doped

Abstract Here we discuss the synthesis of copper (II) oxide (CuO) and manganese (Mn)-doped CuO thin films varying with 0 to 8 at% Mn using the spray pyrolysis technique. As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at% Mn doping. Energy dispersive analysis of X-rays confirmed the chemical composition of the films. X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the ( 11) peak. Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67–2.90 eV and 0.11–1.73 eV, respectively. Refractive index and static dielectric constants were computed from the optical spectra. Electrical resistivity of CuO and Mn-doped CuO (Mn:CuO) thin films was found in the range from 10.5 to 28.6 Ω·cm. The tiniest electron effective mass was calculated for 4 at% Mn:CuO thin films. P to n-type transition was observed for 4 at% Mn doping in CuO films. Carrier concentration and mobility were found in the orders of 1017 cm–3 and 10–1 cm2/(V·s), respectively. The Hall coefficient was found to be between 9.9 and 29.8 cm3/C. The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

scholarly journals The Use of Synchrotron Radiation in the Energy Calibration of Astronomical Apparatus

1972 ◽  
Vol 14 ◽  
pp. 642-646
Author(s):  
G. A. Gurzadyan ◽  
J. B. Ohanesyan
Keyword(s):  
Thin Films ◽  
Synchrotron Radiation ◽  
Electron Energy ◽  
Electron Accelerator ◽  
Energy Calibration ◽  
Ideal Solution ◽  
X Rays ◽  
Special Equipment ◽  
Physics Institute ◽  
Wide Range

The problem of energy calibration of astrophysical apparatus is essential for every or almost every space experiment. The utilization of synchrotron radiation from an electronic accelerator should perhaps be taken as an ideal solution of this problem, if of course, such a possibility is available.Special equipment for the extraction of synchrotron radiation has been devised at the circular electron accelerator with a maximum electron energy of 6 GeV, in the Physics Institute of Erevan (Gurzadyan and Ohanesyan, 1972). The equipment is designed primarily for the energy calibration of astronomical apparatus operating in a vacuum and hard ultraviolet and X rays. However, the equipment can also be applied to a wide range of experiments relating to the physics of solids, crystallography, physics of thin films, X rays, etc.

scholarly journals Synthesis and Characterisation of Thin Films of Bismuth Triiodide for Semiconductor Radiation Detectors

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Alka Garg ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Active Material ◽  
Visible Region ◽  
Radiation Detectors ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
Bismuth Iodide

Bismuth iodide is a potentially active material for room temperature radiation detector, as it is well reported in the literature that it has both wide energy band gap and high atomic absorption coefficient. Crystalline films of high atomic number and high radiation absorption coefficient can absorb the X-rays and convert them directly into electrical charges which can be read by imaging devices. Therefore, it was proposed to grow thin films of Bismuth iodide on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. The structural studies of the films were carried out using XRD and optical absorption measurement was carried out in the UV/VIS region using spectrophotometer. All Bismuth iodide films grown at room temperature are polycrystalline and show X-ray diffraction peaks at angles reported in research papers. The optical transmission spectra of BiI3 films show a high transmission of about 80% in visible region with a sharp fall near the fundamental absorption at 650 nm. Resistivity of the as-grown film was found to be around 1012 ohm-cm suitable value for X-ray detection application. Films were subjected to scanning electron microscopy to study the growth features of both as-grown and annealed films.

scholarly journals Experimentally obtained and computer-simulated X-ray non-coplanar 18-beam pinhole topographs for a silicon crystal

2019 ◽  
Vol 75 (3) ◽  
pp. 483-488 ◽  
Author(s):  
Kouhei Okitsu ◽  
Yasuhiko Imai ◽  
Yoshitaka Yoda
Keyword(s):  
Silicon Crystal ◽  
Dynamical Theory ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Agreement

Non-coplanar 18-beam X-ray pinhole topographs for a silicon crystal were computer simulated by fast Fourier transforming the X-ray rocking amplitudes that were obtained by solving the n-beam (n = 18) Ewald–Laue dynamical theory (E-L&FFT method). They were in good agreement with the experimentally obtained images captured using synchrotron X-rays. From this result and further consideration based on it, it has been clarified that the X-ray diffraction intensities when n X-ray waves are simultaneously strong in the crystal can be computed for any n by using the E-L&FFT method.

scholarly journals Исследование этапов превращения кремния в карбид кремния в процессе атомного замещения методами полного внешнего отражения рентгеновских лучей и рентгеновской дифрактомерии

2022 ◽  
Vol 64 (3) ◽  
pp. 326
Author(s):  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
Е.В. Осипова ◽  
В.М. Стожаров
Keyword(s):  
Structural Quality ◽  
Total External Reflection ◽  
X Rays ◽  
Reflection Method ◽  
X Ray Diffraction ◽  
Modified Technique ◽  
Substitution Method ◽  
X Ray ◽  
Sic Films

X-ray diffraction and total external reflection of X-rays (X-ray reflectometry) methods were used to study the successive stages of synthesis of epitaxial SiC films on Si (100) X-ray diffraction and total external X-ray reflection (XRD) methods were used to study successive stages of synthesis of epitaxial SiC films on Si (100) surfaces, (110) and (111) surfaces by the atom substitution method. The data on the transformation evolution of (100) surfaces were studied, (110) and (111) Si, into SiC surfaces. A comparative analysis of the X-ray structural quality of the SiC layers grown on Si by the atom substitution method with the quality of SiC layers grown by Advanced Epi by the standard CVD method. A modified technique for the total outer X-ray reflection method, based on measurements of the intensity of the reflected X-rays using a special parabolic mirror. It is shown that the method of total external reflection method makes it possible to obtain important information about the degree of surface roughness of SiC layers, the evolution of their crystal structure and plasmon energy in the process of Si to SiC conversion.

Quantitative basis for the rocking-curve measurement of preferred orientation in polycrystalline thin films

2003 ◽  
Vol 36 (3) ◽  
pp. 890-897 ◽  
Author(s):  
H. Toraya ◽  
H. Hibino ◽  
T. Ida ◽  
N. Kuwano
Keyword(s):  
Thin Films ◽  
Density Distribution ◽  
Volume Fraction ◽  
Preferred Orientation ◽  
Crystal Plane ◽  
X Rays ◽  
Rocking Curve ◽  
Polycrystalline Thin Films ◽  
Least Squares Fit ◽  
Quantitative Basis

A quantitative basis for the rocking-curve measurement of the preferred orientation in polycrystalline thin films is presented. Gaussian functions are used for modeling the density distribution of the normals to the crystal plane around the normal to the specimen surface. An intensity formula for the rocking curve is derived from the kinematical theory applied to the case of asymmetric Bragg reflection. The density distribution is determined by the least-squares fit of a theoretical rocking curve to the observed curve, and a volume fraction of crystallites, whose normals to the crystal plane are present within a defined angular range, can be obtained from it. AlN and Au polycrystalline thin films were used for testing the present procedure. Parameter values of the model function, refined using both synchrotron radiation and laboratory X-rays, agree well with each other within the experimental errors although these intensity data sets were collected under different experimental conditions in instrumentation and wavelength. A distribution of depth-dependent preferred orientation in the AlN thin film was revealed by using double-layer and multiple-layer models. A very small degree of preferred orientation in Au thin films could also be measured. Parallel-beam optics and integrated intensities instead of peak height intensities are important for reliable rocking curve measurement.

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