Article
Chemistry, Multidisciplinary
Rafael G. Toscano-Negrette, Jose C. Leon-Gonzalez, Juan A. Vinasco, A. L. Morales, Fatih Koc, Ahmet Emre Kavruk, Mehmet Sahin, M. E. Mora-Ramos, Jose Sierra-Ortega, J. C. Martinez-Orozco, R. L. Restrepo, C. A. Duque
Summary: A theoretical analysis of optical properties in a ZnS/CdS/ZnS core/shell/shell spherical quantum dot was conducted, considering variations of internal dot radius, the application of electric and magnetic fields, as well as the presence of on-center donor impurity. It was found that the transition energy decreases with the growth of internal radius and the increase of external magnetic field, leading to red-shift of resonant peaks. Conversely, the application of electric field resulted in a blue-shift of resonances but a decrease in the amplitude of optical responses. The activation of impurity effects caused a decrease in energy values, particularly impacting the ground state and resulting in an increase in transition energies.
Article
Materials Science, Multidisciplinary
M. Kirak, S. Yilmaz
Summary: This study investigates the combined effects of hydrogenic impurity, core radius and layer thickness, and external electric and magnetic fields on the third harmonic generation (THG) of core/shell/well/shell spherical quantum dots. The study used the 2D finite difference method within the effective mass approximation to obtain wavefunctions and energy values. The results show that the THG coefficient is mainly influenced by the external fields and the sizes of the core, barrier, and well regions. Additionally, the presence of on-center hydrogenic donor impurity significantly reduces the magnitude of THG at certain potential parameter values.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Kobra Hasanirokh, Adrian Radu, Carlos A. Duque
Summary: This article presents a theoretical study on the electronic, impurity-related, and nonlinear optical properties of CdS/ZnS quantum dots under the influence of electric and magnetic fields. The study finds that combined effects of a central electric field and a z-directed magnetic field can result in core/shell-like quantum confinement and oscillations of the electron ground state. The presence of donor impurity suppresses these oscillations and leads to blue shifts and magnifications in the optical properties.
Article
Physics, Multidisciplinary
Zhi-Hai Zhang, Jian-Hui Yuan
Summary: This paper analytically investigates the energy levels and nonlinear optical properties modulated by the applied electric field in a GaAs/GaAlAs hexagonal quantum dot with a hydrogenic impurity. The results show that the energy levels and nonlinear optical absorption of the dot strongly depend on the hydrogenic impurity. The geometric parameter, confinement potential, and applied electric field play crucial roles in the electronic and optical properties of the hexagonal quantum dot.
Article
Physics, Applied
Min Hu, Hailong Wang, Qian Gong
Summary: The hydrogen donor impurity states were calculated in In0.65Ga0.35As0.75P0.25/InP coaxial double quantum well wires using the plane wave method within the theoretical framework of effective mass envelope function approximation. The binding energies and transition energies of impurity states were obtained as functions of impurity position, distance between the inner and outer quantum wires, magnetic and electric field strengths. The effects of quantum wire thickness and distance between quantum wires on impurity states were analyzed in detail, with differential impacts of electric and magnetic fields on the binding energy of impurity states observed depending on the impurity position.
MODERN PHYSICS LETTERS B
(2021)
Article
Materials Science, Multidisciplinary
M. Kirak
Summary: The effects of magnetic field, temperature, potential parameters, and impurity on the magnetic and thermodynamic properties of GaAs quantum dot confined by the parabolic-inverse square plus Gaussian potential were investigated. The study revealed that these factors have a significant influence on the magnetic and thermodynamic properties of the structure.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Multidisciplinary
I. F. I. Mikhail, I. M. M. Ismail, M. M. El Shafee
Summary: The Rashba effect in a spherical quantum dot confined by a radial parabolic potential and subjected to external parallel magnetic and electric fields is investigated. A different approach is applied to derive the solution of the Schrodinger equation in the presence of Rashba interactions, which presents the exact solution in a more accurate manner. The results show that the Rashba interactions significantly affect the electron energy levels and splitting, and their variation with applied fields and Rashba coupling strength is investigated.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Physics, Condensed Matter
E. B. Al, E. Kasapoglu, H. Sari, I Sokmen
Summary: This study investigates the binding energies of hydrogenic donor impurities in a spherical quantum dot under an external magnetic field using the matrix diagonalization method and compact density matrix approximation. The results show that the donor position, magnetic field, and dot size have significant effects on the binding energies and optical absorption coefficients.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
D. Makhlouf, M. Choubani, F. Saidi, H. Maaref
Summary: The study focuses on the design of a resonant lens-shaped InAs/GaAs core/shell quantum dot structure and its effects on nonlinear optical rectification and carrier's transition lifetime. Results show that increasing the core radius improves the NOR coefficient, while the application of electric and magnetic fields enhances the NOR coefficient.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
M. Jaouane, A. Sali, A. Ezzarfi, A. Fakkahi, R. Arraoui
Summary: This theoretical study examines the binding energy of off-center donor impurities in wurtzite InGaN/GaN multilayer cylindrical quantum dots. The study finds that the binding energy is significantly influenced by the electric field, hydrostatic pressure, and magnetic field. The research also reveals that lattice mismatch has an impact on the binding energy, particularly at low pressure.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Physics, Multidisciplinary
Mustafa Kemal Bahar, Pinar Baser
Summary: This study presents the theoretical impact of external parameters on the nonlinear optical properties of a Mathieu quantum dot (MQD) with a screw dislocation and a hydrogenic impurity. The wave equation of the system is solved using the effective mass approximation and the Runge-Kutta-Fehlberg method. The effects of thermodynamic effects, electric and magnetic fields, In concentration, and MQD width on the electronic energy levels and transition frequencies are discussed.
Article
Optics
F. Ungan, M. K. Bahar, M. G. Barseghyan, L. M. Perez, D. Laroze
Summary: This study theoretically investigates the influence of the external electric field on the nonlinear optical properties of a laser dressed cylindrical quantum dot with axial Morse potential. The analysis shows that the system's intraband optical properties closely depend on both the applied external fields and the structural parameters, providing new possibilities for optoelectronic device applications.
Article
Chemistry, Physical
A. Ghanbari, R. Khordad, F. Taghizadeh, I. Nasirizadeh, C. O. Edet, N. Ali
Summary: In this study, the thermal functions of tuned quantum dot/ring systems under an external magnetic field were theoretically investigated. The presence of impurity effect was found to cause peak structures in the specific heat, entropy, and mean energy of the system. The impurity effect was deduced to play a key role in the thermal functions of the system.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
E. B. Al
Summary: In this study, the energies and wavefunctions of a single shallow donor atom in a semiconductor core/shell/shell quantum dot heterostructure were computed using the effective mass approach. The effects of size modulation, donor position, and magnetic field on the absorption coefficients were analyzed, showing significant changes in the linear and nonlinear parts related to specific donor transitions.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Optics
Christian Heyn, A. Radu, J. A. Vinasco, D. Laroze, R. L. Restrepo, V Tulupenko, Nguyen N. Hieu, Huynh Phuc, M. E. Mora-Ramos, J. H. Ojeda, A. L. Morales, C. A. Duque
Summary: Using effective mass, parabolic band approximations and the finite element method, this study investigates the combined effects of electric and magnetic fields on cone-shaped quantum dots. The main findings include the separation of electrons and holes by electric field, significant increase in exciton lifetime by magnetic field, and redshift of photoluminescence energy transition by magnetic field effects. The results show excellent agreement with experimental measurements.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Anjali Vijeata, Ganga Ram Chaudhary, Savita Chaudhary, Ahmad Umar, Sheikh Akbar, Sotirios Baskoutas
Summary: The study uses carbon dots synthesized from the leaves of Ocimum sanctum as an economical and convenient bimodal approach for detecting ciprofloxacin in water resources. The carbon dots show excellent photoluminescence-based behavior and can enhance the fluorescence emission intensity and peak current. The sensor has a linear relationship for ciprofloxacin detection and can be applied as a high-performance dual sensor.
Article
Chemistry, Multidisciplinary
Jingjing Min, Jingwen Zhai, Tieshuan Dong, Dangdang Xu, Yuli Yan, Christos S. S. Garoufalis, Sotirios Baskoutas, Zaiping Zeng, Yu Jia
Summary: By exploring potential derivatives of the parent semiconductors, we have resolved the issue of limited choice in environmental friendly efficient light-emitting materials, which are often heavy-element-containing or indirect bandgap.
Article
Chemistry, Multidisciplinary
Jingwen Zhai, Tieshuan Dong, Yamei Zhou, Jingjing Min, Yuli Yan, Christos S. Garoufalis, Sotirios Baskoutas, Dangdang Xu, Zaiping Zeng
Summary: In this study, it is theoretically demonstrated that efficient band-edge emission can be achieved in colloidal quantum dots (QDs) of groups III-V by introducing a capping shell in the core/shell architecture. The emission edge is dominated by low intensity exciton states before a critical tensile strain is reached, and by high-intensity bright exciton states after crossing the critical strain. This work provides a novel strategy for realizing efficient band-edge emission of indirect semiconductor QDs through shell engineering, which can be implemented using the well-established colloidal QD synthesis technique.
Article
Chemistry, Physical
Vaibhav Gupta, Rajesh K. Yadav, Ahmad Umar, Ahmed A. Ibrahim, Satyam Singh, Rehana Shahin, Ravindra K. Shukla, Dhanesh Tiwary, Dilip Kumar Dwivedi, Alok Kumar Singh, Atresh Kumar Singh, Sotirios Baskoutas
Summary: This manuscript highlights the use of structural assembling to facilitate the generation of solar chemicals and the synthesis of fine chemicals under solar light. It introduces a metal-free activated carbon cloth (ACC)-templated photocatalyst as an alternative technique to overcome the drawbacks of metal-based photocatalysts. The synthesized EC-R@ACC photocatalyst exhibits high efficiency in the photocatalytic reduction of 4-nitro benzyl alcohol and regeneration of reduced forms of NADH cofactor.
Article
Chemistry, Multidisciplinary
Sargis P. Gavalajyan, Grigor A. Mantashian, Gor Ts. Kharatyan, Hayk A. Sarkisyan, Paytsar A. Mantashyan, Sotirios Baskoutas, David B. Hayrapetyan
Summary: The exciton states in a conical GaAs quantum dot were studied using the effective mass approximation and the finite element method. The dependence of the exciton energy on the geometrical parameters of the dot was investigated. The exciton energy, effective band gap, lifetime, Raman scattering, interband light absorption, and photoluminescence spectra were calculated for different sizes of GaAs quantum dots.
Article
Chemistry, Multidisciplinary
Savita Chaudhary, Manisha Kumari, Pooja Chauhan, Ganga Ram Chaudhary, Ahmad Umar, Sheikh Akbar, Sotirios Baskoutas
Summary: A one-pot methodology is developed to synthesize three types of C-dots and their activated counterparts using waste plastic precursors. Optical studies reveal significant changes in the absorption edge and luminescence behavior of the particles. The mode of interaction between C-dots and their ACs is determined using solvent-dependent fluorescence spectroscopy. This investigation provides valuable insights into the emission behavior and potential applications of the particles as fluorescent probes.
Editorial Material
Chemistry, Multidisciplinary
Sotirios Baskoutas
Article
Chemistry, Multidisciplinary
Mohamed El-Yadri, Jawad El Hamdaoui, Noreddine Aghoutane, Laura M. Perez, Sotirios Baskoutas, David Laroze, Pablo Diaz, El Mustapha Feddi
Summary: This study investigates the impact of quantum size and an external magnetic field on the optoelectronic properties of a cylindrical AlxGa1-xAs/GaAs-based core/shell nanowire. The Hamiltonian of an interacting electron-donor impurity system was described using the one-band effective mass model and two numerical methods were employed to calculate the ground state energies: the variational and finite element methods. The system's cylindrical symmetry revealed transcendental equations due to the finite confinement barrier between the core and the shell, leading to the concept of the threshold core radius. The results demonstrate that the optoelectronic properties strongly rely on core/shell sizes and the external magnetic field strength, with the electron's maximum probability of occurrence depending on the threshold core radius value. This threshold radius separates two regions with different physical behaviors, while the applied magnetic field acts as an additional confinement.
Review
Biochemistry & Molecular Biology
Chahat Sharma, Pooja Sharma, Amit Kumar, Yashika Walia, Raman Kumar, Ahmad Umar, Ahmed A. Ibrahim, Mohd. Sayeed Akhtar, Abdulrab Ahmed M. Alkhanjaf, Sotirios Baskoutas
Summary: The excessive use of chemical substances disrupts beneficial microflora in the soil, posing a threat to human and animal health. Pesticides, commonly used in modern agriculture, accumulate in the soil and can negatively impact the overall ecosystem. However, certain microorganisms, such as Diazotrophs, have the capability to degrade pesticides, contributing to a healthier environment.
CHEMISTRY AND ECOLOGY
(2023)
Article
Environmental Sciences
Ahmad Umar, Rajesh Kumar, Pravin S. More, Ahmed A. Ibrahim, Hassan Algadi, Mohsen A. Alhamami, Sotirios Baskoutas, Sheikh Akbar
Summary: A reduced graphene oxide nanocomposite was synthesized and used to prepare PEG-rGO supramolecular assemblies. Gas-dependent electrical properties of these supramolecular assemblies were investigated, and they exhibited excellent sensitivity and selectivity towards benzene, methanol, and H2 gas.
ENVIRONMENTAL RESEARCH
(2023)
Article
Chemistry, Physical
Manjot Kaur, Shafali Singh, Surinder Kumar Mehta, Sushil Kumar Kansal, Ahmad Umar, Ahmed A. Ibrahim, Sotirios Baskoutas
Summary: Here, the synthesis and characterization of g-C3N4/CeO2 heterostructure is reported. The heterostructure showed strong binding affinity towards heavy transition metal ions and demonstrated excellent selectivity. It also exhibited photocatalytic activity for the degradation of tetracycline under visible light. This work provides an effective strategy for the preparation of fluorescent photocatalytic materials for the detection of heavy metal ions and degradation of pollutants.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Manisha Kumari, Kirandeep Banger, Ganga Ram Chaudhary, Savita Chaudhary, Ahmad Umar, Sheikh Akbar, Sotirios Baskoutas
Summary: A simple and convenient sensory platform based on fluorescence quenching and paper-based probe using carbon dots (CQDs) has been developed. The platform shows low detection value, wide linear response, good stability, and repeatability, making it highly sensitive and efficient for the quantitative analysis of monosodium glutamate (MSG) ions. The sensor can detect MSG ions in real food samples, and a portable and highly sensitive sensory platform for visual detection of MSG has also been prepared with LOD as low as 1 nm.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Review
Environmental Sciences
Yajvinder Saharan, Joginder Singh, Rohit Goyat, Ahmad Umar, Ahmad A. Ibrahim, Sheikh Akbar, Sotirios Baskoutas
Summary: Oil spills caused by accidents such as oil container failures, tanker collisions, and ruptured oil pipelines are a significant problem. Recent oil disasters have resulted in considerable economic and human damage. The cleanup of oil-contaminated soil is challenging due to its adherence to silt and the harmful effects of polycyclic aromatic hydrocarbons in oil. Efficient removal techniques are urgently needed to mitigate the negative impact on human health and the environment.
WATER AIR AND SOIL POLLUTION
(2023)
Article
Chemistry, Physical
Eunbi Kim, Ahmad Umar, Sadia Ameen, Rajesh Kumar, Ahmed A. Ibrahim, Mohsen A. M. Alhamami, M. S. Akhtar, Sotirios Baskoutas
Summary: In this study, ZIF-8/GO and ZIF-8/rGO composites were synthesized and characterized for electrochemical sensing of Cu2+ ions. The composites were prepared by dispersing GO or rGO in a solution of Zn(NO3)2·6H2O and 2-methylimidazole in anhydrous methanol. Various techniques were used to investigate the structural, morphological, and chemical properties of the materials. The ZIF-8/GO composite-based Cu2+ ion sensor exhibited superior sensitivity and LOD compared to ZIF-8/rGO and ZIF-8 alone, demonstrating its potential in electrochemical sensing applications.
SURFACES AND INTERFACES
(2023)
Review
Multidisciplinary Sciences
Sumit Malik, Joginder Singh, Rohit Goyat, Yajvinder Saharan, Vivek Chaudhry, Ahmad Umar, Ahmed A. Ibrahim, Sheikh Akbar, Sadia Ameen, Sotirios Baskoutas
Summary: This review provides an overview of the development of biosensors made of nanoparticles (NPs) and their applications in nanotechnology. The combination of NPs and electrochemical techniques has led to the emergence of biosensors with high sensitivity and decomposition power. Various types of NPs, such as noble metal NPs and metal oxide NPs, nanowires, nanorods, carbon nanotubes, quantum dots, and dendrimers, have been used in biosensors.