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Öğe Comparison of theoretical and experimental electronic and optoelectronic properties of HPS compound(IOP Publishing, 2019) Şaş, Emine Babur; Tanış, Emine; Gündüz, Bayram; Kurt, MustafaWe investigated electronic and optoelectronic properties of 1,1,2,3,4,5-Hexaphenyl-1H-silole (HPS) compound for different concentrations and for theoretical (B3LYP and CAM) and experimental methods. Optical parameters such as absorbance band edge, optical band gap and refractive index of the HPS were controlled by concentration. Optical band gap of the HPS decreases from 2.870 to 2.766 eV with increasing concentration. The refractive indices of the HPS were obtained for different concentrations, relations and methods. According to the results obtained, the two theoretical (B3LYP and CAM) results are in harmony with each other, and the experimental and theoretical-B3LYP results are closer to each other. This study contains important and interesting results, especially in terms of comparing the theoretical and experimental electronic and optoelectronic properties of the HPS compound.Öğe A detailed study on the optical properties of 3-benzoyl-7-hydroxy coumarin compound in different solvents and concentrations(Macedonian Journal of Chemistry and Chemical Engineering, 2019) Kurt, Adnan; Gündüz, Bayram; Koca, MuratA coumarin-derived compound, 3-benzoyl-7-hydroxy coumarin (BHYC), is synthesized to determine its optoelectronic properties, including absorbance band edge, optical band gap, transmittance, refractive index, electrical susceptibility, volume-surface energy loss functions and optical/electrical conductance parameters. The absorbance spectra of BHYC in dimethylformamide (DMF) and dimethylsulfoxide ( DMSO) solvents exhibit maximum peaks at 350 and 353 nm, respectively, in the near-ultraviolet region. The absorbance band edge values of BHYC in DMF and DMSO are 2.526 and 2.500 eV, respectively. The optical band gap of BHYC varies from 2.560 to 2.408 eV with increasing molarity. In contrast, the refractive index of BHYC increases from 2.47 to 2.95 with changing molarity. The obtained results show that 3-benzoyl-7-hydroxy coumarin exhibits a semiconductor behavior and it may be an important candidate for many optoelectronic devices, such as diodes, photodiodes and sensors.Öğe Dispersion characteristics of silk fibroin protein polymer(2020) Taşyürek, Lütfü Bilal; Gündüz, BayramSilk is a natural protein fiber and is widely used in textile technology. Apart from textile technology, silk is preferred in many fields and applications such as biomedical because of its superior advantages. In this study, the fibroin silk solution was used as a biomaterial. The refractive indices of silk fibroin (SF) protein polymer were obtained and the refractive index dispersion of the SF protein polymer was analyzed in detail.Öğe Effects of solvents on photonic and fluorescence properties of PtOEP phosphorescent material: Experimental and computational analysis(Elsevier, 2020) Gündüz, Bayram; Bulut, NiyaziThe effects of different solvents (chloroform, tetrahydrofuran, toluene, methanol, acetone and chlorobenzene) on photonic and fluorescence properties of the PtOEP organic phosphorescent material were investigated with experimental and advanced computational techniques. Many parameters such as angle of incidence/refraction, contrast, optical conductance, electrical conductance, peak absorbance, peak emission, stokes shift, fluorescence quantum yield and sensitivity have been obtained. Theoretical and experimental photonic and fluorescence properties of the PtOEP material for different solvents have been compared. It was found that maximum absorbances for experimental and theoretical calculations are quite similar at a value of around 389 (nm) and depending on the solvents used here they slightly shifted to larger wavelength.Öğe The Importance of Polymorphism Dependent Aggregation Induced Enhanced Emission of the Acrylonitrile Derivative: Helical J Type and Antiparallel H Type Stacking Modes(Wiley-Blackwell, 2021) Yakalı, Gül; Çoba, Mustafa B.; Özen, Furkan; Özen, Leyla B.; Gündüz, Bayram; Turgut Cin, GünseliIn this study to analyze the structure-property relationship of synthesized ?-conjugated acrylonitrile derivative in terms of polymorphism dependent emission and conformational polymorphism, single crystal x-ray diffraction method, photophysical and theoretical studies were performed. The fluorescent molecule with two polymorphic structure were presented to demonstrate the effect of the molecular conformation and stacking type on the polymorphism dependent emission in aggregate state. According to results of crystallography and photophysical studies, both form of the molecule displayed aggregation induced enhanced emission (AIEE) property in the solid phase due to the restricted intramolecular rotation (RIR) and favourable stacking interactions including the antiparallel H type, J type stacking modes and intramolecular charge transfer (ICT) process. As a result, J type and antiparallel H type stacking mode with the restricted intramolecular rotation make the crystals higly emissive in solid phase. We believe that, studied two polymorphs will be best candidates for the ?-conjugated acrylonitrile derivatives in the optoelectronic field. Moreover, this study will provide an overview of the importance of conformational polymorphism, stacking type on fluorescence properties of the polymorphic structures and propose new ways for targeted polymorphic molecular design strategies in acrylonitrile derivatives.Öğe NTCDA compounds of optoelectronic interest: Theoretical insights and experimental investigation(Elsevier, 2021) Hssain, Ala Hamd; Gündüz, Bayram; Majid, Abdul; Bulut, NiyaziStructural, electronic, and spectroscopic properties of 1,4,5,8-naphthalene-tetracarboxylic dianhydride organic semiconductor molecule are reported based on experimental and computational methods. The spectroscopic investigations were carried out via H1 and C13 NMR chemical shifts and UV–VIS spectroscopy. The effects of solvation of NTCDA molecule into different solvents were investigated to explore the effect of polarities of solvents on the absorption peak of the compound. Positive charges on the Carbon atom side were discovered to be more prominent, leading to the conclusion that the NTCDA molecule could be suited for optoelectronic applications with mid-range optical band gaps.Öğe Optoelectronic parameters of peripherally tetra-substituted copper(ii) phthalocyanines and fabrication of a photoconductive diode for various conditions(Royal Society of Chemistry, 2020) Günsel, Armağan; Bilgiçli, Ahmet Turgut; Tüzün, Burak; Pişkin, Hasan; Yaraşır, Meryem Nilüfer; Gündüz, BayramIn this study, the molecular structure of 4-(4-(trifluoromethoxy)phenoxy)phthalonitrile (1) has been elucidated and its supra-molecular dynamics have been revealed by the analysis of single crystal X-ray diffraction measurements. Compound (1) and its copper(II) phthalocyanine (2) were theoretically calculated with different basis sets. The Gibbs free energy values of copper(II) phthalocyanine (2) were investigated. The calculated values of IR, NMR and UV-vis spectra for compound (1) and its copper(II) phthalocyanine (2) were compared with the experimentally obtained values. The surface morphology properties of the compound (2) film for different magnifications were examined with its SEM images. We investigated the optical and optoelectronic parameters of compound (2) for different molarities. Also, we fabricated a diode based on compound (2) and examined its electronic characteristics under darkness, room light and 100 mW cm?2. Our diode exhibits a photoconductive property.Öğe A study on Optical Applications of Silk Fibroin Biomaterial(2020) Gündüz, Bayram; Buldurun, KenanSilk ?broin (SF) is a natural substitute used in biological medicine for its good biocompatibility and biodegradability. Compared to other easily degradable (biodegradable) materials, they exhibit excellent properties, such as excellent mechanical properties, optical properties and electrical insulation, which are advantageous in the development of materials made from silk bromine, flexible electronics. In here, optoelectronic parameters such as optical band gap, transmittance, dielectric constant and conductivity components of the silk fibroin solution were obtained and were discussed for biomaterial applications.Öğe A study on the optoelectronic parameters of 4-chloromethyl-7-hydroxy coumarin in various solvents and concentrations(Türkiye Kimya Derneği, 2021) Kurt, Adnan; Gündüz, Bayram; Koca, MuratA coumarin derivative, namely 4-chloromethyl-7-hydroxy coumarin (CMEHC), was synthesized in order to test the concentration and solvent effect on its optical properties. The spectral characterization of this compound was accomplished by FTIR and 1H-NMR techniques. The UV absorption spectra of CMEHC compound in various solvents (THF, DMSO, DMF) were recorded with a UV–VIS spectrophotometer. The optical parameters such as maximum peak position, absorption band edge, and direct allowed bandgap were reported for these solvents and also various concentrations. The lowest direct allowed bandgap was obtained with THF. The absorbance spectra of CMEHC compound were dominant at the near ultraviolet region. The refractive index values were compared with each other using Moss, Ravindra, Herve-Vandamme, Reddy and Kumar-Singh relations.
