Browsing by Author "Surucu, G."
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Article Citation Count: 6Electronic, optical and thermodynamic characteristics of Bi12SiO20 sillenite: First principle calculations(Elsevier Science Sa, 2021) Işık, Mehmet; Surucu, G.; Gencer, A.; Gasanly, N. M.; Department of Electrical & Electronics EngineeringBi12XO20 (X: Si, Ge, Ti) ternary semiconducting compounds are known as sillenites and take a remarkable attention thanks to their attractive photorefractive properties. The present paper reports electronic, optical and thermodynamic characteristics of Bi12SiO20 by means of density functional theory (DFT) calculations. The crystalline structure of the compound was revealed as cubic with lattice constant of 10.135 angstrom. XRD pattern obtained from DFT calculations were compared with experimental data and there is a good consistency between them. The electronic band structure and density of state plots were presented in detail. The band gap energy of the compound was determined from electronic band structure and spectra of optical constants. The spectral dependencies of real and imaginary components of dielectric function, refractive index, extinction coefficient, absorption coefficient and loss function were plotted in the 0-12 eV spectral range. The revealed structural, electronic and optical characteristics were discussed taking into account the previously reported theoretical and experimental studies on the Bi12SiO20 sillenite.Article Citation Count: 25Equiatomic quaternary Heusler compounds TiVFeZ (Z=Al, Si, Ge): Half-metallic ferromagnetic materials(Elsevier Science Sa, 2021) Sürücü, Özge; Surucu, O.; Usanmaz, D.; Khenata, R.; Candan, A.; Surucu, G.; Electrical-Electronics EngineeringEquiatomic quaternary Heusler compounds (EQHCs) are very promising materials for spintronic applications due to their excellent electronic and magnetic properties. In this study, structural, electronic, magnetic, mechanic, and dynamic properties of TiVFeZ (Z=Al, Si, Ge) EQHCs are investigated. Three nonequivalent structural configurations of alpha, beta, and gamma type structures are considered. The gamma is defined as the most stable phase for all these compounds and has a half-metallic character. The predicted Curie temperatures of TiVFeAl, TiVFeSi, and TiVFeGe compounds are about 488 K, 256 K, and 306 K, respectively. We also show that TiVFeZ (Z=Al, Si, Ge) have thermodynamic, dynamic, and mechanical stabilities. The presented results reveal that these compounds are potential materials for spintronics applications. (C) 2021 Elsevier B.V. All rights reserved.Article Citation Count: 0Exploring Temperature-Dependent bandgap and Urbach energies in CdTe thin films for optoelectronic applications(Elsevier, 2024) Sürücü, Özge; Surucu, G.; Işık, Mehmet; Parlak, M.; Isik, M.; Electrical-Electronics Engineering; Department of Electrical & Electronics EngineeringThis study examines CdTe thin films deposited via RF magnetron sputtering, focusing on structural and optical properties. X-ray diffraction, Raman spectroscopy, and SEM assessed structural characteristics. Optical properties were analyzed through transmittance measurements from 10 to 300 K. Tauc plots and Varshni modeling revealed a temperature-dependent bandgap, increasing from 1.49 eV at room temperature to 1.57 eV at 10 K. Urbach energy rose from 82.7 to 93.7 meV with temperature. These results are essential for applications where temperature affects CdTe-based device performance.Article Citation Count: 8First principles study of Bi12GeO20: Electronic, optical and thermodynamic characterizations(Elsevier, 2021) Işık, Mehmet; Surucu, G.; Gencer, A.; Gasanly, N. M.; Department of Electrical & Electronics EngineeringBismuth germanium oxide (Bi12GeO20) is one of the attractive members of sillenite compounds having fascinating photorefractive characteristics. The electronic, optical and thermodynamic properties of Bi12GeO20 were investigated using density functional theory (DFT) calculations. The experimental and calculated X-ray diffraction patterns were obtained as well-consistent with each other. The lattice constant of the cubic crystalline structure of Bi12GeO20 compound was calculated as 10.304 angstrom. The electronic band structure and partial density of states plots were reported and contribution of constituent atoms (Bi12GeO20) to the valence and conduction bands was presented. The band gap energy of the Bi12GeO20 was calculated as 3.20 eV. This wide direct band gap energy provides Bi12GeO20 significant potential in ultraviolet applications. The spectra of real and imaginary components of dielectric function, refractive index, extinction coefficient and absorption coefficient were drawn in the 0-10 eV energy range. Temperature-dependent heat capacity plot indicated the Dulong-Petit limit as 825 J/mol.K. The results of the present study would present worthwhile information to device application areas of Bi12GeO20 compound.Article Citation Count: 0Innovative 2D materials for efficient photocatalysis: A comparative study for WSi2N4, WGe2N4, and their janus counterpart WSiGeN4 monolayers(Pergamon-elsevier Science Ltd, 2024) Sürücü, Özge; Surucu, G.; Lisesivdin, S. B.; Surucu, O.; Altuntas, G.; Bostan, B.; Gencer, A.; Electrical-Electronics EngineeringIn pursuit of environmentally friendly and effective photocatalytic materials for water splitting, this research paper presents a thorough evaluation of WSi2N4, WGe2N4, and their Janus counterpart WSiGeN4 monolayers through the application of Density Functional Theory. The study elucidates the optical, electronic, and structural characteristics of these monolayers, thereby demonstrating their potential as highly favorable contenders for applications involving photocatalytic water splitting. By means of comprehensive optimization and analysis, it is shown that these monolayers possess advantageous characteristics, such as favorable band gaps, stable work functions, and stability over a broad pH range. These attributes are of utmost importance in ensuring the effectiveness of hydrogen evolution reaction (HER). The inclusion of Janus WSiGeN4, which possesses an intrinsic mirror asymmetry, significantly improves the photocatalytic efficacy of the material. This is achieved by meeting the demands of optimal redox reaction levels in both the conduction and valence bands. In conjunction with machine learning force fields, ab initio molecular dynamics (AIMD) simulations validate the thermal stability of these monolayers at 300 K. In addition, our analysis of the optical properties reveals substantial absorption in the visible spectrum - vital for photocatalytic applications powered by solar energy. In summary, the research highlights the potential of Janus WSiGeN4, WGe2N4, and WSi2N4 monolayers as multifunctional and effective substances for forthcoming photocatalytic water -splitting systems. This advancement indicates of a significant stride in the direction of sustainable energy solution development.Article Citation Count: 3Pressure and spin effect on the stability, electronic and mechanic properties of three equiatomic quaternary Heusler (FeVHfZ, Z = Al, Si, and Ge) compounds(Elsevier, 2021) Sürücü, Özge; Gencer, A.; Surucu, O.; Usanmaz, D.; Candan, A.; Electrical-Electronics EngineeringIn this paper, three equiatomic quaternary Heusler compounds -FeVHfZ (Z = Al, Si, and Ge) - are investigated for their structural, magnetic, electronic, mechanic, and lattice dynamic properties under pressure effect. These compounds are optimized for under three structural types and three magnetic phases: beta is the most stable structure with ferromagnetic phase. The electronic properties reveal that FeVHfAl is a half-metal, and that FeVHfSi and FeVHfGe are spin gapless semiconductors. In addition to electronic band structure, possible hybridization and partial density of states are presented. Furthermore, the mechanical properties are studied, and the three-dimensional direction-dependent mechanical properties are visualized under varying pressure effects. Our results reveal the half-metal and spin gapless semiconductor nature of the ferromagnetic FeVHfZ com-pounds, making them promising materials for spintronics applications.