Article
Chemistry, Physical
Laima Trinkler, Dajin Dai, Liuwen Chang, Mitch Ming-Chi Chou, Tzu-Ying Wu, Jevgenijs Gabrusenoks, Dace Nilova, Rihards Ruska, Baiba Berzina, Ramunas Nedzinskas
Summary: The luminescent properties of epitaxial Cu2O thin films were compared with Cu2O single crystals in the temperature range of 10-300 K. The thin films were deposited epitaxially on Cu or Ag substrates with different processing parameters. The luminescence spectra of the thin films showed emission bands corresponding to V-O(2+), V-O(+), and V-Cu defects at approximately 720, 810, and 910 nm, respectively. Additionally, there were unidentified emission bands observed around 650-680 nm.
Article
Chemistry, Physical
Cristiane B. Goncalves, Rafael T. da Silva, Gustavo Dalenogare, Isabelle M. D. Gonzaga, Lucia H. Mascaro, Mateus M. Ferrer, Marcelo Assis, Elson Longo, Hugo B. de Carvalho, Antonio C. Doriguetto
Summary: This study presents a comprehensive analysis of morphology, microstructure, and optical properties of electrodeposited Cu2O thin films on SnO2:F substrates. The films exhibited stability, purity, and crystallinity, with various morphologies and growth orientations. These findings make a significant contribution to the exploration of multifunctional semiconductor materials for various advanced technologies.
SURFACES AND INTERFACES
(2023)
Article
Electrochemistry
Shinichi Yamamoto, Ryoga Yokoyama, Kosuke Imahori, Pei Loon Khoo, Natsuko Asano, Shunsuke Asahina, Tsutomu Shinagawa, Masanobu Izaki
Summary: P-type CuO-Cu2O nanocomposite semiconductors with Cu2O-embedded CuO aggregations and Cu2O aggregation consisting of space-filling CuO grains were fabricated by photoelectrochemical high-frequency potential-switching. The size of CuO and Cu2O grains decreased with an increase in cycle numbers, while maintaining their characteristic monoclinic and cubic lattices. The bandgap energy of CuO components remained constant at 1.5 eV, while the bandgap energy of Cu2O components decreased from 2.05 eV to 1.85 eV due to Cu2+ state incorporation. The CuO-Cu2O nanocomposites exhibited ionization energy of approximately 5.2 eV and work function of approximately 4.6 eV, which were close to those of single CuO and Cu2O layers.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Alper Cetinel, Gokhan Utlu
Summary: In this study, a Cu2O/ZnO heterojunction was fabricated on porous silicon (PSi) using a two-step electrochemical deposition technique. The PSi/Cu2O/ZnO nanostructure was systematically investigated, and it was found that the morphology of ZnO nanostructures was significantly affected by the applied current density, while those of Cu2O nanostructures remained unchanged. XRD analysis revealed that the polycrystallinity and preferential orientation of ZnO nanostructures changed with the deposition time. The I-V analysis showed that the PSi/Cu2O/ZnO samples exhibited rectifying junction and acted as a characteristic p-n heterojunction. Among the experimental parameters, the PSi/Cu2O/ZnO samples obtained at 0.5 mA current density and 80 min deposition time showed the best junction quality and defect density.
Article
Physics, Multidisciplinary
Ziqing Li, Changcai Cui, Xiaolong Zhou, Subiao Bian, Oriol Arteaga, Xipeng Xu
Summary: In this study, the thickness and optical properties of amorphous carbon films deposited on a-plane sapphire substrates were investigated non-destructively using Mueller matrix spectroscopic ellipsometry. The films were characterized using topography profilometry and Raman spectroscopy. Two fitting models, Bruggeman effective medium approximation model and single Cody-Lorentz oscillator model, were proposed to determine the film thickness and optical constants. The results were verified using Transmission Electron Microscope (TEM). The findings showed that non-destructive measurement of film thickness was possible in the range of 5 nm to 200 nm, with some error for thin films due to nonuniform deposition. However, after 4 hours of deposition, the relative error between TEM and Spectroscopic Ellipsometry measurements reduced to 1%, indicating the potential of spectroscopic ellipsometry in monitoring thickness growth.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Inorganic & Nuclear
Meriem Aloui, Loubna Mentar, Abdelkrim Beniaiche, Amor Azizi
Summary: Cu2O polyhedrons with two different shapes were synthesized using the galvanostatic electro-chemical deposited method. These polyhedrons exhibit well-defined crystallographic faces and high photoelectrochemical stability. The influence of potassium chloride on the structural, morphological, conduction type, and optical properties of Cu2O nanostructures were investigated, revealing the effect of chloride ions on carrier density and morphology.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Electrochemistry
Nuur Syahidah Sabran, Iman Aris Fadzallah, Mohd Faizul Mohd Sabri, Takahito Ono, Khairul Fadzli Samat, Siti Nor Farhana Yusuf, Rahman Saidur
Summary: In this study, electrodeposition and post-deposition annealing techniques were utilized to optimize Skutterudite thick films, demonstrating that higher molecular weight PVA assistance and high-temperature annealing can significantly improve the thermoelectric properties of the material, achieving a substantial increase in the Seebeck coefficient, S, and power factor, PF.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
T. A. Zidan, L. M. El-Khlawany, E. M. El-Menyawy
Summary: The chemical synthesis and optical properties of N,N-dimethylquinacridone were investigated, with surface characteristics and optical properties of DMQA at different thicknesses found to vary, and the intensity of absorption bands increasing with film thickness.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Materials Science, Multidisciplinary
Steffen Wilbrandt, Olaf Stenzel, Abrar Liaf, Peter Munzert, Stefan Schwinde, Sven Stempfhuber, Nadja Felde, Marcus Trost, Tina Seifert, Sven Schroeder
Summary: Aluminum thin films with thicknesses between approximately 10 and 60 nm were deposited using evaporation and sputtering techniques. The layer characterization focused on reflectance, optical constants, and surface quality. A thickness dependence of the optical constants was established in the investigated thickness range.
Article
Green & Sustainable Science & Technology
Binghao Wang, Zhiqiang Chen, Feng Zhao
Summary: In this study, semiconductor oxide cuprite (Cu2O) and indium tin oxide (ITO) heterojunction solar cells were fabricated and characterized. The introduction of a titanium (Ti) thin film buffer layer improved the surface morphology, resistivity, and contact potential of the Cu2O film. The Cu2O/Ti/ITO solar cell exhibited enhanced photovoltaic performance and increased power conversion efficiency compared to the Cu2O/ITO solar cell.
Article
Electrochemistry
Akhilender Jeet Singh, Garima Aggarwal, Sushobhita Chawla, Chandan Das, K. R. Balasubramaniam
Summary: The nucleation and growth mechanism of Cu2O on metal oxide and metal substrates is studied, revealing the influence of electrolyte pH and deposition potential. The orientation of Cu2O films strongly depends on the electrolyte pH and potential, with preferred (100) orientation at pH 9 and (111) orientation at high applied potential on metal oxide substrate. The grain size of Cu2O decreases with potential on metal oxide substrate, while it increases on metal substrate, possibly due to the difference in active nucleation sites. The nucleation and growth at pH 12 are influenced by diffusion and lattice incorporation, resulting in predominantly (111) oriented films on both substrates.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Karolina Syrek, Magdalena Jazdzewska, Marcin Koziel, Leszek Zaraska
Summary: The characteristics of cuprous oxide thin films prepared by electrodeposition at different temperatures were studied. It was found that increasing the electrodeposition temperature not only increased the growth rate of the oxide, but also affected its crystalline orientation preference. The study also revealed that the photoelectrochemical cathode synthesized at the highest temperature had superior performance, likely due to its higher deposit thickness and material texture. Additionally, the potential of using such photocathodes for solar light-induced ammonia synthesis was demonstrated.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Fariba Moshtaghi, Mardali Yousefpour, Ali Habibolahzadeh
Summary: Polyaniline-Bi-Sb-Te-Se thin films were fabricated on aluminum substrate using electrodeposition and electrochemical reaction method. The structure and morphology of the films were analyzed by FTIR, XRD, FE-SEM, and EDS. The electrical and thermoelectric properties of the films were evaluated, and it was found that the chemical composition and applied potential greatly influenced the thermoelectric properties. Furthermore, a slight change in the chemical compound improved the thermoelectric properties by approximately 65%.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Walter Giurlani, Martina Vizza, Antonio Alessio Leonardi, Maria Jose Lo Faro, Alessia Irrera, Massimo Innocenti
Summary: This work demonstrates the optimal conditions for electrodeposition of a CdSe film on n-Si and studies the structural and optical properties of the films before and after annealing. Significant enhancement of photoluminescence is observed after annealing, opening up possibilities for integrating other materials in silicon manufacturing processes for optoelectronic device fabrication.
Article
Engineering, Electrical & Electronic
Yiwei Zhou, Jian Zhao, Yejing Liu, Ray J. H. Ng, Joel K. W. Yang
Summary: In this study, 3D nanoporous inverse opal structures were successfully fabricated by electroplating method using a uniform polystyrene (PS) opal template. The material composition of the inverse opals can be controlled to consist of pure Cu, Cu2O or Cu2O-Cu composites, showing a low-angle-dependent photonic band. Additionally, Cu2O-Cu hybrid inverse opals exhibit higher separation efficiency of photogenerated carriers and double layer capacitance compared to pure Cu or Cu2O inverse opals.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Mathematics
Devaraj Vivek, Elsayed M. Elsayed, Kuppusamy Kanagarajan
Summary: This paper studies the existence and attractivity of solutions for an implicit differential equation with composite fractional derivative. Sufficient conditions for the main results are investigated using Schauder's fixed point theorem. An example is presented to illustrate the theory.
GEORGIAN MATHEMATICAL JOURNAL
(2023)
Article
Automation & Control Systems
K. Ramkumar, K. Ravikumar, E. M. Elsayed
Summary: This work discusses the optimal control for a class of Hilfer fractional stochastic integrodifferential systems driven by Rosenblatt process and Poisson jumps in infinite dimensional space involving the Hilfer fractional derivative. First, the existence and uniqueness of mild solution results are proved using fractional calculus, successive approximation method, and stochastic analysis techniques. Second, the optimal control for the proposed problem is presented using Balder's theorem. Finally, an example is demonstrated to illustrate the obtained theoretical results.
JOURNAL OF CONTROL AND DECISION
(2023)
Article
Chemistry, Physical
Ahmed I. Abdel-Salam, Sayed Y. Attia, Saad G. Mohamed, Fouad I. El-Hosiny, M. A. Sadek, M. M. Rashad
Summary: The purpose of this study is to improve the electrochemical performance of supercapacitors by designing and exploring novel active electrode materials. A hierarchical structure of nickel-cobalt-sulfide nanostructures (NiCo2S4) decorated on electrospun N-doped carbon nanofiber (CNF), called NiCo2S4@CNF, was fabricated using a one-step hydrothermal approach. The NiCo2S4@CNF hierarchical structure exhibited a large surface area and high porosity, serving as ion diffusion channels, resulting in high specific capacitance and specific capacity values. The NiCo2S4@CNF//CNF hybrid supercapacitor demonstrated superior energy density and stability, making it a promising electrode material for supercapacitor applications.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Amal G. Mahdy, Abeer A. Emam, E. A. Mussa, A. Y. Abdel-All, M. M. Rashad, Aya M. Abuelftooh, Saad G. Mohamed
Summary: The nanoscale Li2Mn0.8Ni0.2SiO4/MnO2 composite was successfully synthesized via a two-step method, involving the preparation of MnO2 nanoparticles and the synthesis of Li2Mn0.8Ni0.2SiO4 using an EDTA-assisted sol-gel method. The nanocomposite exhibited an orthorhombic crystal structure with a Pmn2(1) space group and mesoporous properties. The electrode showed excellent electrochemical performance, making it a promising candidate for high-efficiency energy storage electrode materials.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Engineering, Chemical
Hesham A. Hassan, Ali Omar Turky, Ali M. Hassan, Hosni A. G. Ahmed, Mohmed. M. Rashad
Summary: Titanium-substituted lanthanum strontium manganite (LSMO) nanoparticles with titanium ratios of 0.1, 0.2, 0.3, 0.4, and 0.5 were prepared using an organic acid precursor pathway. The insertion of titanium led to an increase in crystallite size, change in optical properties, and an increase in band gap energy. The refractive index, however, slightly decreased with increased titanium concentration.
PARTICULATE SCIENCE AND TECHNOLOGY
(2023)
Article
Mathematics
Khalil S. Al-Basyouni, Elsayed M. Elsayed
Summary: The aim of this paper is to derive analytic expressions for solutions of rational difference equations, such as xn+1 = 1 +/- (x(n-1)y(n))/(1 - y(n)), y(n+1) = 1 = (y(n-1)x(n))/(1 - x(n)), x(n+1) = 1 +/- (x(n-1)y(n-2))/(1- y(n)), y(n+1) = 1 +/- (y(n-1)x(n-2))/(1 - x(n)), where the initial conditions x(-2), x(-1), x(0), y(-2), y(-1), y(0) are non-zero real numbers. In addition, it is shown that some of these systems exhibit different periods. Theoretical outcomes are verified through numerical applications and results are graphically illustrated using mathematical programs.
Article
Mathematics
Turki D. Alharbi, Elsayed M. Elsayed
Summary: The theory of difference equations plays an important role in applicable analysis, and studying the qualitative behavior of these equations has become an increasingly fruitful research area attracting many researchers. This paper demonstrates the stability and existence of periodic solutions in nonlinear difference equations, and provides numerical simulations to validate the results.
INTERNATIONAL JOURNAL OF ANALYSIS AND APPLICATIONS
(2023)
Article
Mathematics
S. Harikrishnan, D. Vivek, E. M. Elsayed
Summary: This study investigates integro-differential equations of arbitrary order using the ?-Hilfer type proportional fractional operator. The research aims to expose the dynamic behavior of fractional order integro-differential equations, including the existence, uniqueness, and stability of solutions. The results are proven using the initial value problem and nonlocal conditions.
JOURNAL OF CONTEMPORARY MATHEMATICAL ANALYSIS-ARMENIAN ACADEMY OF SCIENCES
(2023)
Article
Engineering, Multidisciplinary
E. M. Elsayed, B. S. Alofi
Summary: The aim of this paper is to derive formulas for solutions of fractional systems of difference equations with non-zero real initial values. In addition, we prove that some of these systems exhibit different periodicities. We also validate our theoretical results with numerical examples and illustrate the findings using famous mathematical programs like Matlab.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Mathematics, Interdisciplinary Applications
Sahar Albosaily, Elsayed M. Elsayed, M. Daher Albalwi, Meshari Alesemi, Wael W. Mohammed
Summary: In this study, we consider the (3+1)-dimensional stochastic potential Yu-Toda-Sasa-Fukuyama with conformable derivative (SPYTSFE-CD) forced by white noise. We use He's semi-inverse and improved (G ' / G)-expansion methods to study different types of solutions for SPYTSFE-CD. The potential Yu-Toda-Sasa-Fukuyama theory has the potential to explain various scientific phenomena related to solitons and nonlinear waves in dispersive media, plasma physics, and fluid dynamics. We provide numerous 2D and 3D figures to demonstrate how white noise affects the pattern formation and stability of solutions for SPYTSFE-CD.
FRACTAL AND FRACTIONAL
(2023)
Article
Mathematics, Interdisciplinary Applications
Wael W. W. Mohammed, Clemente Cesarano, Elsayed M. M. Elsayed, Farah M. M. Al-Askar
Summary: The Fokas system with M-truncated derivative (FS-MTD) was analyzed in this study using the extend F-expansion approach and the Jacobi elliptic function method to obtain analytical solutions in the forms of elliptic, rational, hyperbolic, and trigonometric functions. These solutions can be used to analyze a wide range of physical processes related to nonlinear pulse transmission in monomode optical fibers. The impacts of MTD on the solutions were illustrated using 2D and 3D figures.
FRACTAL AND FRACTIONAL
(2023)
Article
Computer Science, Information Systems
N. Suresh Babu, B. Ravivarma, E. M. Elsayed, K. G. Sreekumar
Summary: Rank distance codes have wide applications, especially in network coding. This paper proposes a new class of rank distance codes over the real number field, which can be used in various applications. From this class, a subclass of equidistant constant rank codes applicable in network coding is extracted, and an upper bound for some optimal rank distance codes is determined.
JOURNAL OF ELECTRICAL AND COMPUTER ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Mohamed A. Nawwar, Magdy S. Abo Ghazala, Lobna M. Sharaf El-Deen, Badawi Anis, Abdelhamid El-Shaer, Ahmed Mourtada Elseman, Mohamed M. Rashad, Abd El-hady B. Kashyout
Summary: GeSn compounds have been widely studied in photodetectors due to their detection limit in the NIR and mid-IR region. In this article, p-i-n structures based on GeSn junctions were fabricated and the impact of As and Sn doping on the strain characteristics of GeSn was studied. The direct transitions and tuning of their band energies were investigated, and the barrier height and spectral responsivity were controlled with the incorporation of As. The heterojunctions prepared showed spectral responses in the near UV and NIR regions, making them suitable for UV and NIR photodetection applications.
Article
Chemistry, Multidisciplinary
E. M. Elsayed, Ashraf K. Eessaa, M. M. Rashad, S. M. Abdelbasir, A. M. El-Shamy
Summary: Nanocrystalline zinc oxide (ZnO) films were electrodeposited onto indium doped tin oxide (ITO) substrates using aqueous solutions of zinc nitrate at temperatures ranging from 25 0C to 75 0C. Linear sweep voltammetry and chronopotentiometry techniques were used to investigate the deposition process and the effects of different factors. Temperature and current were found to have a significant influence on the growth of ZnO films. The nucleation mechanism was found to be instantaneous at potentials between -800 and -1200 mV, and non-instantaneous and gradual at voltages higher than -1400 mV. X-ray analysis confirmed the presence of Zincite phase with a crystallite size of 61 nm, and the films exhibited a smooth and compact surface.
EGYPTIAN JOURNAL OF CHEMISTRY
(2023)
