WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - Scopus: 1A Perspective on the State-Of Functionalized 2d Materials(American Institute of Physics, 2023) Duran, Tuna; Yayak, Yankı Öncü; Aydın, Hasan; Peeters, François M.; Yağmurcukardeş, MehmetTwo-dimensional (2D) ultra-thin materials are more crucial than their bulk counterparts for the covalent functionalization of their surface owing to atomic thinness, large surface-to-volume ratio, and high reactivity of surface atoms having unoccupied orbitals. Since the surface of a 2D material is composed of atoms having unoccupied orbitals, covalent functionalization enables one to improve or precisely modify the properties of the ultra-thin materials. Chemical functionalization of 2D materials not only modifies their intrinsic properties but also makes them adapted for nanotechnology applications. Such engineered materials have been used in many different applications with their improved properties. In the present Perspective, we begin with a brief history of functionalization followed by the introduction of functionalized 2D materials. Our Perspective is composed of the following sections: the applications areas of 2D graphene and graphene oxide crystals, transition metal dichalcogenides, and in-plane anisotropic black phosphorus, all of which have been widely used in different nanotechnology applications. Finally, our Perspectives on the future directions of applications of functionalized 2D materials are given. The present Perspective sheds light on the current progress in nanotechnological applications of engineered 2D materials through surface functionalization. © 2023 Author(s).Article Citation - WoS: 4Citation - Scopus: 4Photonic Crystal Textiles for Heat Insulation(American Institute of Physics, 2023) Çetin, Zebih; Tunçtürk, Yiğit; Sözüer, Hüseyin SamiIn this work, we have studied transmission properties of a photonic crystal-like structure that can be woven into fabrics. An interesting possibility emerges when considering the potential energy savings through suppression of radiation. It is a well-established fact that every object at a finite temperature inherently emits electromagnetic waves. Within the specific context of the human body, radiation takes on a crucial role as a fundamental mechanism governing heat dissipation. Thus, exploring ways to manage or mitigate this radiation could offer innovative approaches to optimize energy consumption and enhance heat regulation. It is well known that a photonic crystal can block electromagnetic energy with a specific frequency that is falling into a photonic bandgap. By using the numerical method called a finite-difference time domain, we have shown that this property of a periodic structure can be used to make textiles to save energy that is used to heat a human body environment. Numerical calculations have shown that by using the proposed photonic crystal structure, 53 % of electromagnetic energy is reflected. Although we mainly focused on textiles, it is worth highlighting that the same fundamental principle can be extended to diverse fields; for example, this structure can be integrated with construction materials and effectively function as a radiation heat insulator. © 2023 Author(s).Article Citation - WoS: 4Citation - Scopus: 4The Peculiar Potential of Transition Metal Dichalcogenides for Thermoelectric Applications: a Perspective on Future Computational Research(American Institute of Physics, 2023) Özbal, Gözde; Sarıkurt, Sevil; Sevinçli, Haldun; Sevik, CemThe peculiar potential transition metal dichalcogenides in regard to sensor and device applications have been exhibited by both experimental and theoretical studies. The use of these materials, thermodynamically stable even at elevated temperatures, particularly in nano- and optoelectronic technology, is about to come true. On the other hand, the distinct electronic and thermal transport properties possessing unique coherency, which may result in higher thermoelectric efficiency, have also been reported. However, exploiting this potential in terms of power generation and cooling applications requires a deeper understanding of these materials in this regard. This perspective study, concentrated with this intention, summarizes thermoelectric research based on transition metal dichalcogenides from a broad perspective and also provides a general evaluation of future theoretical investigations inevitable to shed more light on the physics of electronic and thermal transport in these materials and to lead future experimental research. © 2023 Author(s).Article Citation - WoS: 3Citation - Scopus: 2Effects of Interphase Boundaries in Ginzburg-Landau One-Dimensional Model of Two-Phase States in Clamped Systems(American Institute of Physics, 2021) Levanyuk, Arkady P.; Minyukov, Sergey A.; Mısırlıoğlu, İbrahim Burç; Okatan, Mahmut BarışPrevious Landau-type models of two-phase state formation in clamped systems whose material exhibits first-order phase transitions in free state neglects the existence of interphase boundaries. Here, we take them into account in the framework of a Ginzburg-Landau one-dimensional model to study the dependence of characteristics of the two-phase state on system size. Unlike earlier works, we find that the transition to the two-phase state from both the symmetrical and nonsymmetrical phases is not continuous but abrupt. For a one-dimensional system with length L studied in this work, we show that the formation of two-phase state begins with a region whose size is proportional to root L. The latent heat of the transition is also proportional to root L -> infinity, recovering the earlier result for infinite systems. The temperature width of the two-phase region decreases with decreasing of L, but we are unable to answer the question about the critical length for two-phase state formation because the approximation used in analytical calculations is valid for sufficiently large L. A region of small values of L was studied partially to reveal the limits of validity of the analytical calculations. The main physical results are also obtainable within a simple approximation that considers the energy of interphase boundary as a fixed value, neglecting its temperature dependence and the thickness of the boundary. A more involved but consistent treatment provides the same results within the accepted approximation and sheds light on the reason of validity of the simplified approach.Article Citation - WoS: 2Citation - Scopus: 2Room Temperature Emission From Single Defects in Wo3 Enhanced by Plasmonic Nanocrystals(American Institute of Physics, 2021) Özçeri, Elif; Polat, Nahit; Balcı, Sinan; Tarhan, EnverRoom temperature light emission from optically active defect centers in two-dimensional layered materials has attracted great interest in recent years owing to the critical applications in the field of quantum information technologies. Therefore, efficient generation, detection, characterization, and manipulation of spatially localized emission from the defect centers are of crucial importance. Here, we report localized, stable, and bright room temperature photoluminescence (PL) emission from defects in WO3. In particular, the experimentally observed polarized and power dependent PL emission shows single photon characteristics. In addition, density functional theory calculations indicate that the source of the emission is most probably oxygen vacancy defects in WO3. The PL emission obtained from the localized defect centers in WO3 at room temperature has been, further, enhanced more than 20 times by using plasmonic gold nanoparticles.Article Citation - WoS: 2Non-Relativistic Lee Model in Two-Dimensional Riemannian Manifolds(American Institute of Physics, 2012) Erman, Fatih; Turgut, Osman TeomanThis work is a continuation of our previous work [F. Erman and O. T. Turgut, J. Math. Phys. 48, 122103 ( 2007)], where we constructed the non-relativistic Lee model in three-dimensional Riemannian manifolds. Here we renormalize the two-dimensional version by using the same methods and the results are shortly given since the calculations are basically the same as in the three-dimensional model. We also show that the ground state energy is bounded from below due to the upper bound of the heat kernel for compact and Cartan-Hadamard manifolds. In contrast to the construction of the model and the proof of the lower bound of the ground state energy, the mean field approximation to the two-dimensional model is not similar to the one in three dimensions and it requires a deeper analysis, which is the main result of this paper. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705355]Conference Object The Effect of Ag and Ag Plus N Ion Implantation on Cell Attachment Properties(American Institute of Physics, 2009) Urkaç, Emel Sokullu; Öztarhan, Ahmet; Tıhmınlıoğlu, Funda; Deliloğlu, İsmet Gürhan; İz, Sultan Gülce; Oks, Efim; Ila, DaryushImplanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.Conference Object Thermal Behaviour of W Plus C Ion Implanted Ultra High Molecular Weight Polyethylene (uhmwpe)(American Institute of Physics, 2009) Urkaç, Emel Sokullu; Öztarhan, Ahmet; Tıhmınlıoğlu, Funda; Ila, Daryush; Budak, S.; Chhay, B.; Nikolaev, A.The aim of this work was to examine thermal behavior of the surface modified Ultra High Molecular Weight Poly Ethylene (UHMWPE) in order to understand the effect of ion implantation on the properties of this polymer which is widely used especially for biomedical applications. UHMWPE samples were Tungsten and Carbon (W+C) hybrid ion implanted by using Metal Vapour Vacuum Arc (MEVVA) ion implantation technique with a fluence of 10 17 ions/cm2 and extraction voltage of 30kV. Untreated and surface-treated samples were investigated by Rutherford Back Scattering (RBS) Analysis, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectrometry, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). This study has shown that ion implantation represents a powerful tool on modifying thermal properties of UHMWPE surfaces. This combination of properties can make implanted UHMWPE a preferred material for biomedical applications.Article Citation - WoS: 3Citation - Scopus: 4Experimental and First-Principles Investigation of Cr-Driven Color Change in Cesium Lead Halide Perovskites(American Institute of Physics, 2019) Özen, Sercan; Güner, Tuğrul; Topçu, Gökhan; Özcan, Mehmet; Demir, Mustafa Muammer; Şahin, HasanHerein, we report room temperature Cr-doping for all-inorganic perovskites that have attracted great attention in recent years due to their extraordinary optical properties, low cost, and ease of synthesis. Incorporation of Cr 3 + ions into the perovskite crystal lattices is achieved by following a facile route involving an antisolvent recrystallization method at room temperature. It is shown that both Cr-doping and formation of crystals in the CsPbBr x Cl 3 - x phase are provided by increasing the concentration of the CrCl 3 solution. It is also observed that the doping procedure leads to the emergence of three types of distinctive peaks in the PL spectrum originating from CsPbBr x Cl 3 - x domains (476-427nm), Cr-strained host lattices (515nm), and midgap states formed by Cr dopants (675-775nm). It is also found that the Cr-doped perovskites emitting a dark violaceous color change their color to white with a high color rendering index (88) in 30-day time intervals. Easy-tunable optical properties of all-inorganic Cs perovskites indicate their great potential for future optoelectronic device applications.Article Citation - WoS: 234Citation - Scopus: 234Quantum Properties and Applications of 2d Janus Crystals and Their Superlattices(American Institute of Physics, 2020) Yağmurcukardeş, Mehmet; Qin, Y.; Özen, Sercan; Sayyad, M.; Peeters, François M.; Tongay, S.; Şahin, HasanTwo-dimensional (2D) Janus materials are a new class of materials with unique physical, chemical, and quantum properties. The name "Janus" originates from the ancient Roman god which has two faces, one looking to the future while the other facing the past. Janus has been used to describe special types of materials which have two faces at the nanoscale. This unique atomic arrangement has been shown to present rather exotic properties with applications in biology, chemistry, energy conversion, and quantum sciences. This review article aims to offer a comprehensive review of the emergent quantum properties of Janus materials. The review starts by introducing 0D Janus nanoparticles and 1D Janus nanotubes, and highlights their difference from classical ones. The design principles, synthesis, and the properties of graphene-based and chalcogenide-based Janus layers are then discussed. A particular emphasis is given to colossal built-in potential in 2D Janus layers and resulting quantum phenomena such as Rashba splitting, skyrmionics, excitonics, and 2D magnetic ordering. More recent theoretical predictions are discussed in 2D Janus superlattices when Janus layers are stacked onto each other. Finally, we discuss the tunable quantum properties and newly predicted 2D Janus layers waiting to be experimentally realized. The review serves as a complete summary of the 2D Janus library and predicted quantum properties in 2D Janus layers and their superlattices.