Article
Chemistry, Multidisciplinary
Hao Xu, Wei Zhu, Mingliang Tang, Xiangyuan Wang, Yin Zhang
Summary: This study investigated a multi-component oxide glass consisting of 50B(2)O(3)-(25-x)Al2O3-10Na(2)O-xBi(2)O(3)-15CaF(2)-0.5Dy-0.5Eu (x = 0 , 5 , 10 , 15 , 20 , 25 mol%). The fluoroborate glass exhibited non-crystallinity, as confirmed by X-Ray diffraction. FTIR spectra revealed the structural properties of the glass, characterized by the stretching and vibrating groups of various boric groups. The optical band gap measurements confirmed the presence of unbridged oxygen (NBOs) in the glass samples. The refractive index of the fluoroborate glass increased with the Bi2O3 content, and the glass exhibited strong emission in the blue, yellow, and red range. The emission spectra were analyzed to calculate chromaticity coordinates, color temperature, color rendering index, and color purity. By adjusting the Bi2O3 content and excitation wavelength, the glass was able to emit white light, making it suitable for white light-emitting diodes (WLEDs).
MATERIALS TODAY CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Bakhtiar Ul Haq, Salem AlFaify, R. Ahmed, Muhammad Haider Khan, M. M. Alsardia, I. B. Khadka, Se-Hun Kim
Summary: In this study, the polytypism of gallium phosphide (GaP) was explored to generate new polytypes with structures resembling SiC, wz, sp, and β-BeO. These polytypes demonstrated promising absorption capabilities for visible and UV light, along with good dynamical stability. The predictions suggest that the novel polytypes of GaP could be useful for electronic and optoelectronic devices.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Chemistry, Physical
H. Joshi, R. K. Thapa, Amel Laref, Worasak Sukkabot, Lalrinthara Pachuau, Lalmuanpuia Vanchhawng, P. Grima-Gallardo, M. Musa H-E Saad, D. P. Rai
Summary: First Principles calculations were performed on CsPbBr3 to investigate its elastic, electronic and optoelectronic properties. The results show that the calculated energy bandgap is similar to experimentally measured values and the optical spectra exhibit high absorption coefficients in the range of 3-6 eV.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Physical
Mohamed A. Helal, H. M. El-Sayed, Ahmed A. Maarouf, Mohamed M. Fadlallah
Summary: The study investigated the impact of different pore structures on 2D-TMD using density functional theory, revealing higher stability for smaller pores, lattice deformation and decreased Young's modulus with increasing pore size. Certain systems exhibited magnetism due to missing metal atoms, while the emergence of metal states at pore edges resulted in some systems being half-metallic. Oxygen passivation restored metallic behavior in the systems.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Maudud Ahmed, Shubharaj Mukherjee, Tukai Singha, P. M. G. Nambissan
Summary: In this study, cadmium oxide nanocrystallites with sizes ranging from 16 nm to 30 nm were synthesized via a chemical precipitation method at different synthesis temperatures. X-ray diffraction analysis confirmed the absence of mixed or impurity phases. The samples exhibited quantum confinement effects, as demonstrated by the variation in band gap energies measured by optical absorption. The presence of defects, such as non-stoichiometric defects, was found to greatly influence the properties of the nanocrystallites, and their concentration was quantified using positron annihilation studies.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Xingyue Zhangyang, Lei Liu, Zhisheng Lv, Feifei Lu, Jian Tian
Summary: A theoretical model for the photoemission of field-assisted AlGaN heterojunction nanorod array photocathodes has been established, which improves electron collection efficiency by up to 42.3%. The model discussed in this article can provide theoretical references for the design and manufacture of high-efficiency solar-blind ultraviolet detectors.
Article
Nanoscience & Nanotechnology
Daniel B. Straus, Robert J. Cava
Summary: By using solid-state synthesis, the band gap of halide perovskite CsPbBr3 can be continuously widened through homovalent substitution, allowing its optical properties to be tailored for absorptive and emissive applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Spectroscopy
S. L. Nogueira, H. Santos Silva, J. P. Lere-Porte, F. Serein-Spirau, T. Jarrosson, J. R. Tozoni, A. Marletta, R. A. Silva
Summary: This paper presents a systematic study on the determination of the optical gap energy in luminescent p-conjugated polymers. The results show the presence of polymer-polymer interactions in both solution and solid-state film, and successfully obtain the optical gap energy of the isolated polymer.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Materials Science, Multidisciplinary
S. Ktifa, M. Rahmani
Summary: This work investigates the morphology and optical properties of vanadium pentoxide (V2O5) nanoparticles deposited on silicon nanowires (SiNWs). SiNWs are obtained by metal-assisted chemical etching (MACE) method. The deposition of V2O5 on SiNWs is done using a vacuum thermal evaporation system for different durations. Snowball-like V2O5 nanoparticles are observed on the SiNWs surface, with increased condensation of V2O5 elements over longer evaporation durations. Raman and Fourier transform infrared (FTIR) spectroscopies analyze the changes in bonds and chemical composition of the SiNWs-V2O5 nanocomposites. X-ray Diffraction (XRD) technique confirms the orthorhombic structure of the V2O5 layer. SiNWs-V2O5 composites exhibit strong emission in the visible range due to radiative band edge transitions of V2O5, leading to an increased photoluminescence (PL) intensity similar to that of SiNWs. The optical band gap (Eog) increases from 1.851 to 2.075 eV with the presence of V2O5 on the SiNWs surface, attributed to the Burstein-Moss effect.
Article
Crystallography
Thouraya Salah, Noureddine Mhadhbi, Ali Ben Ahmed, Besma Hamdi, Najeh Krayem, Mohamed Loukil, Ahlem Guesmi, Lotfi Khezami, Ammar Houas, Naoufel Ben Hamadi, Houcine Naili, Ferdinando Costantino
Summary: Single crystals of a new organic-inorganic hybrid compound (C3H7N6)2[ZnCl4]H2O were synthesized and characterized. The crystal structure consists of inorganic layers built from tetrachloridozincate anions [ZnCl4](2) and free water molecules. The compound shows promising antimicrobial and enzymatic inhibition activities.
Article
Materials Science, Multidisciplinary
Pawan Kumar, Devender Singh, Isha Gupta
Summary: Pure single phasic cool green light emitting Tb3+ activated GdSr2AlO5 nanophosphors were successfully synthesized via an effective gel-combustion method. Characterization techniques including XRD, SEM, TEM, EDX spectroscopy, photoluminescence, decay life time, and colorimetric analysis were used to study the fabricated nanomaterials. The results showed the formation of tetragonal crystal structure with the space group of I4/mcm and the nano-sized nature of the particles. The efficient energy transfer between Gd3+ and Tb3+ ions resulted in a strong excitation band at 273 nm and a green emission at 548 nm, making these nanophosphors suitable for optical display and lighting applications.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Physics, Multidisciplinary
Oles Matsyshyn, Francesco Piazza, Roderich Moessner, Inti Sodemann
Summary: By combining the techniques of nonequilibrium Green functions and Floquet theory, we demonstrate the existence of a well-defined periodic steady state leading to finite rectified currents in the weak coupling to a thermal bath regime. In this Rabi regime, the rectified current scales as the square root of the radiation intensity, allowing for easy diagnosis in experiments. Moreover, our description provides a smooth interpolation from ideal periodic Gibbs ensemble describing Rabi oscillations to the perturbative regime with rapid relaxation due to strong coupling to a thermal bath.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Noori S. Anad, Zakaria M. Abd El-Fattah, M. Attallah, Hanaa M. Ahmed, M. M. El-Okr, H. H. El-Bahnasawy
Summary: Pristine and chromium-doped ZnO nanowires were synthesized using the co-precipitation method, and their properties were characterized using various techniques. The study showed that chromium doping had minimal effect on the optical band gap, and the successful doping was confirmed through spectroscopic analysis.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Jun-Jie Wang, Can Fu, Hai-Yang Cheng, Xiao-Wei Tong, Zhi-Xiang Zhang, Di Wu, Li-Miao Chen, Feng-Xia Liang, Lin-Bao Luo
Summary: The study introduces a non-wide band gap semiconductor ultraviolet photodetector utilizing silicon nanowire arrays, which exhibit sensitivity to UV light but insensitivity to visible and infrared light. This novel device shows promise for sensitive UV photodetectors, with characteristics comparable to or even better than traditional wide band gap semiconductor devices.
Article
Materials Science, Ceramics
Jun Yuan, Guoshuai Zhao, Shiqi Ren, Yongjin Wu, Fengya Hu, Qingru Wang, Qiang Shi, Bing Yang, Shuhong Li, Dong Zhang
Summary: SrTiO3:Eu3+-ZnTiO3:Mn4+ nanocomposites were successfully synthesized for highly sensitive optical thermometers. The structure of SrTiO3:Eu3+ and ZnTiO3:Mn4+ nanophosphors remained unchanged after heat treatment. The emission intensity of Eu3+ and Mn4+ showed different temperature dependencies.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Applied
Manjari Garg, Tejas R. Naik, C. S. Pathak, S. Nagarajan, V. Ramgopal Rao, R. Singh
APPLIED PHYSICS LETTERS
(2018)
Article
Chemistry, Physical
C. S. Pathak, J. P. Singh, R. Singh
CHEMICAL PHYSICS LETTERS
(2018)
Article
Engineering, Electrical & Electronic
A. K. Das, S. Hajra, M. K. Mandal
Summary: The paper discusses the encryption of RGB color images using microcontroller ATMEGA 32 synchronized with a one-dimensional chaotic map. Two microcontrollers are used to execute encryption and decryption algorithms under synchronized condition to demonstrate the cryptosystem. The security of the algorithm is analyzed using various cryptanalysis techniques to assess its strength.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
C. S. Pathak, Manjari Garg, J. P. Singh, R. Singh
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2018)
Article
Computer Science, Artificial Intelligence
Debashis Nandi, Jayashree Karmakar, Amish Kumar, Mrinal Kanti Mandal
IET IMAGE PROCESSING
(2019)
Article
Engineering, Electrical & Electronic
M. Kar, A. Kumar, D. Nandi, M. K. Mandal
IETE TECHNICAL REVIEW
(2020)
Article
Optics
Dhoumendra Mandal, Sumana Mandal, Mrinal Kanti Mandal, Sisir Kumar Garai
OPTICAL ENGINEERING
(2019)
Article
Engineering, Electrical & Electronic
Sumana Mandal, Dhoumendra Mandal, Mrinal Kanti Mandal, Sisir Kumar Garai
JOURNAL OF COMPUTATIONAL ELECTRONICS
(2019)
Article
Computer Science, Information Systems
J. Karmakar, D. Nandi, M. K. Mandal
MULTIMEDIA TOOLS AND APPLICATIONS
(2020)
Article
Energy & Fuels
Stav Alon, Maayan Sohmer, Chandra Shakher Pathak, Iris Visoly-Fisher, Lioz Etgar
Summary: This study focuses on the two-step deposition of mesoporous-carbon-based perovskite solar cells, investigating the influence of dipping time on photovoltaic parameters and achieving a power conversion efficiency of up to 15%. While stability degradation over time was observed at maximum power point tracking, a complete recovery of the devices in the dark was noticed, attributed to the shrinkage of perovskite's unit cell during the recovery process.
Article
Engineering, Electrical & Electronic
Jayashree Karmakar, Arghya Pathak, Debashis Nandi, Mrinal Kanti Mandal
Summary: This work introduces a novel spatial compression method for video signals, integrating sparse representation with hyper-chaotic DNA coding-based encryption module to enhance security and efficiency. Through testing and comparison with other systems, it is demonstrated that the proposed algorithm outperforms others in terms of efficiency, quality, and security.
DIGITAL SIGNAL PROCESSING
(2021)
Article
Chemistry, Physical
Chandra Shakher Pathak, Gopinath Paramasivam, Florian Mathies, Katrin Hirselandt, Vincent Schroeder, Oliver Maus, Janardan Dagar, Carola Klimm, Eva Unger, Iris Visoly-Fisher
Summary: This study reports on the fabrication and optimization of Cs(0.05)FA(0.79)MA(0.16)Pb-20 (Br0.17I0.83)(3) perovskite solar cells using spin-coating and inkjet printing as deposition methods, and examines the effects of adding the polymer PTB7. It was found that inkjet-printed devices with added PTB7 exhibited higher power conversion efficiency compared to those without the polymer additive, indicating improved quality of the perovskite layers. In contrast, the effect of the polymer additive on spin-coated samples was obscured, but the incorporation of PTB7 had a positive effect on the opto-electronic quality of the thin films.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Arghya Pathak, Jayashree Karmakar, Debashis Nandi, Mrinal Kanti Mandal
Summary: This paper addresses the issue of mismatching features and intensity in the process of image inpainting and presents a novel inpainting method based on sparse representation technique. Experimental results confirm the superiority of the proposed method.
SIGNAL IMAGE AND VIDEO PROCESSING
(2023)
Article
Chemistry, Physical
Hyuntae Choi, Haeryang Lim, Heesu Kim, Jeongin Lim, Minji Park, Chandra Shakher Pathak, Seulki Song
Summary: After the introduction of spiro-OMeTAD as a hole transport material, the efficiency of perovskite solar cells (PSCs) has greatly improved. However, spiro-OMeTAD is vulnerable to moisture and heat, and its high cost hinders the commercialization of PSCs. Thus, there is a growing demand for dopant-free and cost-effective hole transport materials. P3HT meets these criteria, but PSCs with P3HT show lower efficiency compared to those with spiro-OMeTAD. To address this issue, a dual functional molecule called octylammonium azide (OAN(3)) was synthesized and used, resulting in PSCs with an efficiency of 20.0% and better long-term stability compared to bare PSCs.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Optics
Sumana Mandal, Dhoumendra Mandal, Mrinal Kanti Mandal, Sisir Kumar Garai
JOURNAL OF OPTICS-INDIA
(2018)
