Semnan University PressProgress in Physics of Applied Materials2783-47943220231201Erbium doped Barium Tungstate-Chitosan Nanocomposite: Luminescent Properties119123830310.22075/ppam.2023.31808.1065ENSanazAlamdariDepartment of Nanotechnology, Semnan University, Semnan, Iran P.O. Box: 35131-19111MohammadHemmatiFaculty of Physics, Semnan University, P.O. Box:35195‑363, Semnan, IranMajidJafar TafreshiFaculty of Physics, Semnan University, P.O. Box:35195‑363, Semnan, IranMohammad HosseinEhsaniFaculty of Physics, Semnan University, P.O. Box:35195‑363, Semnan, IranJournal Article20230916Recently, there has been an increase in the ability to adjust the optical band gap and enhance the brightness of luminescence in nanophosphors that are used in light-emitting diodes and detectors. In this study, a flexible nanocomposite of erbium-doped barium tungstate (BaWO<sub>4</sub>:Er-1at.%) thin film was synthesized via co-precipitation method, and the structural and luminescence properties were investigated. The effect of excitation wavelength ( ) was studied on the optical properties of the synthesized composite at room temperature. Doped nanocomposite showed the best visible emission in the blue-green range at excitation wavelength =250) of a xenon lamp and a strong violet emission under 980 nm laser excitation. The XRD results verified the presence of BWO, in the chitosan composite structure. FESEM images showed that the prepared hybrid nanocomposite's surface was smooth, consistent, and compact; The Er:BWO particles exhibited a flower-like morphology. These findings demonstrate the potential for employing this nanocomposite in the fabrication of high-performance optoelectronic devices.https://ppam.semnan.ac.ir/article_8303_e7bfb32fff872969291c6fd9d437566a.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Doped t-J model of twisted bilayer WSe2125130831710.22075/ppam.2023.32414.1070ENMohammad HosseinZareDepartment of Physics, Qom University of Technology, Qom, IranHamidMosadeqDepartment of Physics, Faculty of Science, Shahrekord University, Shahrekord, IranJournal Article20231126Experiments in twisted materials have shown evidence of exotic phases, such as correlated insulating phases and unconventional superconductivity states. Recently, the topological moiré valance bands with opposite Chern numbers in twisted bilayer WSe have been described with a generalized Kane-Mele model on a honeycomb lattice. Interaction strength, band filling, and bandwidth of twisted materials are well controlled employing varying the twist angle and using three-dimensional dielectric environments. To describe the existence of these exotic phases in the twisted bilayer WSe , we consider the doped moiré Hubbard model in the strongly correlated limit. Here, we are interested in studying the stability of different superconductivity channels by employing the mean-filed theory. We find that the admixture of the nearest-neighbor- - and next-nearest-neighbor- -wave pairings is the superconducting ground state at any doping level. In addition, the obtained results show that the quasi-spin-orbit interaction plays an essential role in the stability of this mixed singlet-triplet superconductivity.https://ppam.semnan.ac.ir/article_8317_309ec3eb7669263edd6222473a9cbef9.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Influence of Temperature Dependence of Electrical Conductivity of Graphite Crucible in Czochralski Crystal Growth: A Numerical Analysis131139833210.22075/ppam.2023.32556.1073ENSanazHadidchiPhysics Department, Bu-Ali Sina University, Hamedan 65174, I.R. IranMohammad HosseinTavakoliPhysics Department, Bu-Ali Sina University, Hamedan 65174, I.R. IranJournal Article20231205Graphite crucibles are widely used in induced crystal growth systems. This study examines the impact of temperature variation on the electrical conductivity of the graphite crucible and its influence on the temperature field and melt flow in a Czochralski germanium crystal growth furnace using the two-dimensional finite element method. The in-depth analysis demonstrates that the temperature-dependence of electrical conductivity of the crucible is crucial in the growth process and the thermal field of the setup. Specifically, it is noted that temperature changes have a significant effect on the generation and distribution of induction heat, the temperature and melt flow field, the complex shape of the crystal-melt interface, as well as the stress and dislocations in the grown crystal. These findings highlight the intricate relationship between temperature, crucible conductivity, and the dynamics of the crystal growth process, providing insight into the subtle factors that impact the quality and properties of the resulting crystal.https://ppam.semnan.ac.ir/article_8332_7e0d3536a5f74773dc207598b60a578b.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Design and fabrication of multi-layers antireflection coating consisting of MgF2 and SiO2141146833410.22075/ppam.2023.32214.1067ENHassanSalmaniannezhadLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranDepartment of Physics, Shahid Beheshti University, Tehran, IranHosseinSalmaniannezhadLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranDepartment of Physics, Shahid Beheshti University, Tehran, IranRezaZarei MoghadamDepartment of Physics, Faculty of Sciences, Arak University, Arak, IranMohammadrezaKhaniLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranDepartment of Physics, Shahid Beheshti University, Tehran, IranMahdiArdaniLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranDepartment of Physics, Shahid Beheshti University, Tehran, IranBabakShokriLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranDepartment of Physics, Shahid Beheshti University, Tehran, IranJournal Article20231101In this research, MgF<sub>2</sub> and SiO<sub>2</sub> thin films were prepared by the magnetron sputtering method on glass and ITO substrates. The crystal structure, morphology, and antireflection performance of the coatings were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet spectrophotometry (UV-vis) techniques, respectively. Furthermore, by utilizing both experimental characterization and optical film design tools, the best experimental parameters for every coating were identified. FESEM images confirmed proper growth of the layers on the substrates. EDAX analysis revealed that the manufactured layer consisted of Magnesium fluoride and silica. The study of optical properties demonstrated that the average transmission in the 400-1000 nanometer range exceeded 99%, indicating good agreement with theoretical results. Furthermore, the use of ITO as the substrate reduced the bandgap.https://ppam.semnan.ac.ir/article_8334_22c57328765b29ab1e308c421c669cfe.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Chitosan - Carbon Nanotube - Maghemite nanocomposites – A Flexible Negative Dielectric Constant Material147158834110.22075/ppam.2023.31641.1064ENSaravananAnnamalaiDepartment of Physics, Bharath Institute of Higher Education and Research, Chennai - 600 073Radha PerumalRamasamyDepartment of Physics
Anna University, CEG Campus, Chennai - 600 025Journal Article20230830In this work, the nanocomposites of chitosan containing carbon nanotubes (CNT) and maghemite nanoparticles have been prepared by solution casting method. Techniques such as Raman spectroscopy, SEM, TEM, dielectric relaxation spectroscopy, and VSM studies were made. The incorporation of CNT in to the chitosan matrix and also the interaction between the CNT and the maghemite nanoparticles were studied using Raman spectroscopy. The dielectric constant of Chitosan-CNT composites turned from positive to negative at low frequency when CNT concentration increased from 10 to 20wt%. Interestingly, addition of 20wt% of maghemite nanoparticles into the Cs-CNT nanocomposites affected both the dielectric property and the conductivity of the composite. VSM measurement shows that the prepared maghemite nanoparticles and the Cs-CNT-maghemite nanocomposites are superparamagnetic materials. Observed dielectric characteristics and the electrical conductivity of the samples have been explained by using a model. Tuning of negative permittivity in the chitosan-CNT nanocomposites by using maghemite nanoparticles could be useful as metamaterials.https://ppam.semnan.ac.ir/article_8341_037b2508b553fae45e95622a879d43b8.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Strategies to Improve Photovoltaic Performance of “Green” CuInS2 Quantum Dots159168834210.22075/ppam.2023.32263.1068ENAsgharJamshidi ZavarakiFaculty of New Sciences and Technologies, University of Tehran, North Kargar Street, Tehran, IranJingHuangDepartment of Theoretical Chemistry & Biology, School of Biotechnology, Royal Institute of Technology (KTH), Stockholm, SwedenBoXuOrganic Chemistry, Centre of Molecular Devices, Department of Chemistry, School of Chemical Science and Engineering, Royal Institute of Technology (KTH), Stockholm, SwedenLichengSunOrganic Chemistry, Centre of Molecular Devices, Department of Chemistry, School of Chemical Science and Engineering, Royal Institute of Technology (KTH), Stockholm, SwedenHansAgrenDepartment of Physics and Astronomy, Uppsala University, Uppsala, SwedenJournal Article20231106While nanocrystals in group II-IV semiconductors have been extensively studied as photosensitizers in quantum dot-sensitized solar cells (QDSCs), their practical use is severely hampered by the high toxicity of the heavy metals, like Cd, Pb, and Hg, present in these semiconductors. Our present work is based on a proposition to use a “green” alternative to the currently used sensitizers, namely CuInS<sub>2 </sub>which is a low-toxic semiconductor. However, as for many other types of QDs, surface defects limit also their photovoltaic performance. Therefore, in order to passivate the surface defects and improve the performance of CuInS<sub>2</sub> QDs we explore in this work two strategies - ZnS shell coating and hybrid passivation. The results show that although ZnS shell coating can effectively passivate the surface defects, the electron injection from QDs to TiO<sub>2</sub> nanoparticle is also hampered. Moreover, the size of CuInS<sub>2</sub> QDs is increased after the shell coating, which also is unfavorable for the enhancement of the solar cells efficiency. In contrast, hybrid passivation can passivate the surface defects on the CuInS<sub>2</sub> QDs without size changing, and can increase the loading efficiency of the QDs simultaneously. Consequently, the efficiency of the solar cells is improved to 4.7%, which is a promising result for the green CuInS<sub>2</sub> based QDSCs. Therefore, in addition to the most used shell coatings of CuInS<sub>2</sub> QDs, hybrid passivation may be an effective way for improving their photovoltaic performance. This study employs two strategies “hybrid passivation and ZnS shell coating” and discuss about their effect in solar cell efficiency.https://ppam.semnan.ac.ir/article_8342_71849c40d4d56db0167e759f9b8c6eb1.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Comparison of thermoelectric properties of armchair germanene nanoribbon and armchair germanene nanomesh169176834310.22075/ppam.2023.32472.1072ENRezaKalamiSchool of Physics, Damghan University, Damghan, IranSeyed AhmadKetabiSchool of Physics, Damghan University, Damghan, IranJournal Article20231128This study investigates the thermoelectric properties of pristine armchair germanene nanoribbons (AGeNR) and those defected by quantum antidot arrays (AGeNM). The researchers employed a tight-binding model and the non-equilibrium Green’s function formalism to conduct the study. AGeNM structures were created by introducing quantum antidot arrays in the form of symmetric and asymmetric rhomboid shapes in the central region of the pristine nanoribbons and their electrodes. The study reveals that different AGeNMs exhibit varying band gaps, influencing their electronic and thermoelectric behaviors. It is important to note that the presence of quantum antidot arrays introduces scattering of electrons and phonons in the nanoribbons, resulting in new thermoelectric properties such as the Seebeck coefficient, electrical conductance, electron and phonon thermal conductance, and ZT factor. The symmetry of the quantum antidot array shapes significantly influences the system’s thermoelectric properties. The study paves the way for the development of more efficient nanoscale thermoelectric devices.https://ppam.semnan.ac.ir/article_8343_c611a400b6b49da5f3e93525a5ebfba3.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Surface characterization of Al thin film dependent on the substrate using fractal geometry177183834410.22075/ppam.2023.32439.1069ENMahsaFakharpourDepartment of physics, Maybod branch, Islamic Azad University, Maybod, IranMaryamGholizadeh ArashtiDepartment of Physics, Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, IranSaeedHesami TackallouDepartment of Biology, Central Tehran Branch, Islamic Azad University, Tehran, IranBabakZamaniDepartment of Physics , Central Tehran Branch, Islamic Azad University, Tehran, IranJournal Article20231126In this paper, Al films were deposited on glass and steel substrates by using thermal evaporation technique. X-ray diffraction (XRD) analysis was used for structural characterization of Al thin films. It was found that the growth process mechanism of Al film on two substrates was different. The difference in the growth mechanism and microstructures affects the surface properties. Atomic force microscope (AFM) and field emission scanning electron microscope (FESEM) have been used to describe the surface morphology and fractal properties of Al films. The fractal properties obtained by autocorrelation function (ACF), height-height correlation function (H(r)) and Minkowski function are described and compared with each other. The results of 2D AFM images show that the Al film on the steel substrate has higher surface roughness, roughness exponent, and lateral correlation length compared to the glass substrate. However, the Al film on the glass substrate has a higher spatial complexity with a fractal dimension of D<sub>f </sub>= 2.88.https://ppam.semnan.ac.ir/article_8344_c68d3eaf2511e6b38cc07499b825bae1.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Influence of Zinc Concentration and Sulfurization on the Physical Properties of CZTS Thin Films: Synthesis and Characterization185194834510.22075/ppam.2023.32622.1077ENMahsa SadatSarmalekSchool of Physics, Damghan University, Damghan, IRANMehdiAdelifardSchool of Physics, Damghan University, Damghan, IRANJournal Article20231212This study focused on the synthesis and characterization of CZTS thin films using a spray pyrolysis method followed by sulfurization. Three different samples were prepared by varying the molar ratios of zinc to tin: Cu<sub>2</sub>ZnSnS<sub>4</sub> (PV), Cu<sub>2</sub>Zn<sub>0.9</sub>Sn<sub>1.1</sub>S<sub>4</sub> (NC), and Cu<sub>2</sub>Zn<sub>1.1</sub>Sn<sub>0.9</sub>S<sub>4</sub> (PC). The samples were annealed in the presence of sulfur at 300℃. X-ray diffraction (XRD) analysis revealed the formation of a kesterite crystal structure in all samples, with the (112) plane being the dominant orientation. The CZTS thin films showed a maximum crystallite size of 11.6 nm in the PC sample. Field emission scanning electron microscopy (FESEM) was used to investigate the morphological properties, providing insights into the surface characteristics and microstructure of the thin films. The optical properties of the CZTS thin films were examined using UV-Vis spectroscopy. It was observed that the band gap energy increased in all samples after sulfurization, ranging from 1.50 eV to 1.66 eV. This indicates the potential suitability of the films as absorber layers in solar cell applications. The electrical properties were evaluated through Hall effect measurements, which revealed that the CZTS thin films exhibited p-type conductivity. The NC sample demonstrated the lowest specific resistivity of 1.43 Ω.cm.https://ppam.semnan.ac.ir/article_8345_37f284be9096772104b53651d2cad8b2.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Application of CdTe/CdS/ZnS core/multi-shell QDs as a high-performance nanocatalyst for degradation of methylene blue from water195201839010.22075/ppam.2023.32683.1078ENFarzadFarahmandzadehDepartment of physics, Science Faculty, Vali-E-Asr University of Rafsanjan, Rafsanjan, IranGolnooshAhmadibagheriDepartment of physics, Science Faculty, Vali-E-Asr University of Rafsanjan, Rafsanjan, IranAydaKhoshghamatDepartment of physics, Science Faculty, Vali-E-Asr University of Rafsanjan, Rafsanjan, IranElhamMolahosseiniDepartment of physics, Science Faculty, Yazd University, Yazd, IranMehdiMolaeiDepartment of physics, Science Faculty, Vali-E-Asr University of Rafsanjan, Rafsanjan, IranJournal Article20231215The application of nanocatalysts for the removal of dyes from industries' wastewater and effluents has attracted great attention these days. In this paper, CdTe/CdS/ZnS core/multi-shell quantum dots were used as a nanocatalyst for the degradation and removal of methylene blue, methylene orange, and rhodamine b dyes from water. The obtained results showed that CdTe/CdS/ZnS nanocatalyst had excellent ability for removal of methylene blue dye from water and after 60 min reaction time, methylene blue dye was completely degraded (100%). Also, the degradation percentage of rhodamine b and methylene orange dyes was obtained at about 80.2% and 55.2%, respectively. The radical scavenger experiment was used to study which active radicals play a key role in the photocatalyst process of CdTe/CdS/ZnS nanocatalyst with methylene blue dye and results showed that electrons play a key role in the degradation process. The successful formation of CdTe/CdS/ZnS core/multi-shell QDs was studied by XRD, EDS, PL, absorbance, and TEM analysis. https://ppam.semnan.ac.ir/article_8390_f4a91b086568fed8c475ee69d9675e13.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201Synthesis of CuO and Ce-doped CuO nanosheets; characterization, optical and magnetic properties203209839110.22075/ppam.2023.32447.1071ENHasanKhaleghiDepartment of Basic Sciences, Semnan Branch, Islamic Azad University, Semnan, IranJournal Article20231126In this article, the structural, magnetic, and optical properties of CuO doped by cerium metal ions as a rare earth element synthesized by the hydrothermal method have been investigated. Various techniques such as X-ray diffraction (XRD) along with Rietveld refinement analysis, energy dispersive X-ray analysis (EDX), and field emission scanning electron microscopy (FESEM) have been used to investigate the crystalline and morphological properties. The results demonstrated that the samples crystallized in the form of polycrystalline and nanosheets with a monoclinic structure. Rietveld refinement of the sample showed sensible accord among the experimental data and standard CuO lattice constants. Also, the existing elements are evenly distributed on the surface of the sample and no impurity elements were observed in the material. By using UV-Vis absorption spectroscopy, the optical band gap of the sample was calculated at an acceptable value. To investigate the magnetic properties, a vibrating sample magnetometer (VSM) was carried out, which showed the weak ferromagnetic property of the Ce-doped sample.https://ppam.semnan.ac.ir/article_8391_84b093649b3569e187aa2890cc614596.pdfSemnan University PressProgress in Physics of Applied Materials2783-47943220231201A Graphene and Nickel-Cobalt Metal Organic Framework Composite as a high-performance electrode material for supercapacitor application211216839210.22075/ppam.2023.32594.1075ENShivaSalehiDepartment of Physics, Faculty of Science, Central Tehran Branch, Islamic Azad University, Tehran, IranIsaKarimzadehDepartment of Physics, Faculty of Science, Central Tehran Branch, Islamic Azad University, Tehran, IranJournal Article20231207A high-performance Ni, Co-MOF-G/nickel foam was fabricated using a novel electrodeposition method and used as an electrode material for a supercapacitor application. Structural tests including powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman results affirmed the formation of the electrode active materials. Scanning electron microscopy (SEM) images showed a flower-like Ni, Co-MOF inside graphene sheets forming a composition of active materials on the nickel foam substrate. The electrochemical performance of the Ni, Co-MOF-G/ Nickel foam was examined using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). The prepared electrode delivered approvable specific capacitance of 1158 F g<sup>-1</sup> at the current density of 2 A g<sup>-1</sup> in three molar potassium hydroxides. Excellent storage capacity of the fabricated electrode is attributed to the synergetic effects of bi-metal metal organic frameworks (Ni, Co-MOF) with porous carbon materials (graphene).https://ppam.semnan.ac.ir/article_8392_6b1338b7d7e7d790c4cff5552e8ca635.pdf