Person: ERDEM, MURAT
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ERDEM
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MURAT
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Publication Metadata only Synthesis and characterization of the novel 4-(1-(pyridin-4-yl) ethoxyl) substituted bis(phthalocyaninato) rare earth complexes and investigation of their two-photon absorption-based third-order non-linear optical properties(ELSEVIER, 2022) GÖRK, GÜLŞEN; Cavus, Aleyna; Gork, Gulsen; Erdem, Murat; Ozer, MetinNovel 4-(1-(pyridin-4-yl) ethoxyl) substituted double-decker rare earth phthalocyanine complexes were synthesized starting from (R)-4-(1-(pyridin-4-yl) ethoxy) phthalonitrile with proper rare earth metal acetates in octanol catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene at 300 degrees C. The new starting phthalonitrile compound was obtained from (R)-1-(pyridin-4-yl) ethan-1-ol and 4-nitrophthalonitrile in acetonitrile at reflux temperature in the presence of potassium carbonate as a catalyst. The characterization of the synthesized and isolated compounds was performed by elemental analysis, infrared, ultraviolet visible, proton and correlation spectroscopy nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Nonlinear optical responses of all complexes are investigated using the Z-scan method. The nonlinear absorption coefficient, two-photon absorption cross-section, and the imaginary part of the nonlinear susceptibility of complexes are calculated for each discrete concentration. All these nonlinear parameters of our rare-earth coordinated doubledecker phthalocyanines present a decrement due to the aggregation under high optic powers, which result in sequential two-photon absorption for smaller ionic radii. (c) 2021 Elsevier B.V. All rights reserved.Publication Metadata only Nonlinear optical behavior and optical power limiting characteristics of peripheral symmetrical and non-symmetrical zinc phthalocyanines with nanosecond pulsed excitation(PERGAMON-ELSEVIER SCIENCE LTD, 2021) GÖRK, GÜLŞEN; Erdem, Murat; Korkmaz, Eda; Kosoglu, Gulsen; Ahmetali, Erem; Farajzadeh, Nazli; Eryurek, Gonul; Kocak, Makbule BurkutIn this study, the optical nonlinear absorption and optical limiting performances of symmetrical and non-symmetrical zinc phthalocyanines in tetrahydrofuran (THF) solution were conducted by the open aperture z-scanning technique. A new non-symmetrically substituted metallophthalocyanine, namely 2(3)-[(4- nitrophenyl)ethynyl]-{9(10),16(17),23(24)-tris-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyani-nato}zinc(II) (1b), was synthesized and then characterized by applying different spectroscopic methods, such as FT-IR, H-1 NMR and MALDI-TOF spectroscopy. According to the literature, {2(3),9(10),16(17),23(24)-tetrakis-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyaninatolzin(II) (1a), {2,3,9,10,16,17,23,24-octakis-(3,5-bis(trifluomethyl)phenoxy)-phthalocyaninato}zinc(II) (2a) and 2(3)-[(4-nitrophenyl)ethynyl]-{9,10,16,17,23,24-hexakis-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyani nato}zinc(II) (2b) were prepared. The effect of the symmetry and substituent's number on the nonlinear behavior was determined. A Nd:YAG laser, nanosecond pulsed at 532 nm, was used as the excitation source. The measurements of the input-output power and the nonlinear transmission properties were carried out for different excitation power values and different concentrations of the phthalocyanines in the THF solution. The nonlinear absorption coefficient of beta and the imaginary part of the third order nonlinear susceptibility of the medium (X-3) were found to be strongly dependent on the concentration. All the zinc phthalocyanine complexes showed good optical limiting performances, attributed to a reverse saturable absorption (RSA) process. The results indicate that the zinc phythcyanine complexes are promising candidates for optical limiting materials. (C) 2020 Elsevier Ltd. All rights reserved.Publication Metadata only Upconversion Yb3+/Er3+:La2Ti2O7 phosphors for solid-state lighting and optical thermometry(Elsevier B.V., 2022) ERDEM, MURAT; Erdem M., Cantürk S.B., Eryürek G.The solid-state reaction was employed as a suitable method to produce orthorhombic Yb3+/Er3+ co-doped La2Ti2O7 phosphors. The pump power and temperature dependencies of spectra of the Yb3+/Er3+ co-doped La2Ti2O7 were studied for color tunability and optical thermometry. The pump power significantly affected the color coordinates of the phosphors. The upconversion green light transformed to the broad white light at higher pump power. A two-photon transition was proposed to explain the upconversion energy transfer process. The fluorescence intensity ratio technique was used to calculate the optical temperature sensor sensitivities. The ΔE energy difference obtained from the intensity ratios of the thermally coupled 2H11/2 and 4I15/2 energy levels of Er3+ are 763.64 ± 76.62 cm−1, 777.77 ± 44.62 cm−1, 640.71 ± 137.39 cm−1 for La1.95Yb0.04Er0.01Ti2O7, La1.94Yb0.04Er0.02Ti2O7, and La1.93Yb0.04Er0.03Ti2O7, respectively. Absolute temperature sensitivities of the phosphors decreased with increasing Er3+ concentration. The maximum absolute sensitivity was determined to be 0.51x10-2 K−1 at 553 K for La1.95Yb0.04Er0.01Ti2O7, 0.64x10-2 K−1 at 571 K for La1.94Yb0.04Er0.02Ti2O7, and 0.38x10-2 K−1 at 457 K for La1.93Yb0.04Er0.03Ti2O7. © 2022 Elsevier B.V.Publication Metadata only Investigation of spectral output of Er3+ and Yb3+/Er3+ doped TeO2-ZnO-BaO glasses for photonic applications(ROYAL SOC CHEMISTRY, 2021) ESMER, KADİR; Dogan, Anil; Yildirim, Saniye Merve; Erdem, Murat; Esmer, Kadir; Eryurek, GonulEr3+ and Yb3+/Er3+ doped TeO2-ZnO-BaO glasses were synthesized using the melt quenching technique with two different Er3+ concentrations. The refractive index was calculated to be around 2.14 from the optical band gap energies of the glasses. Under 975 nm laser excitation, weak blue, strong green and red emissions were observed in the visible region, while broadband emission around 1530 nm was recorded in the near infrared region. The increase in red emission intensity as a result of energy transfer from Yb3+ ions to Er3+ ions in Yb3+/Er3+ co-doped glasses is clearly reflected in the change in color coordinates. The temperature sensing abilities of the glasses were determined from the intensity ratios of light emitted from thermally coupled energy levels (H-2(11/2) and S-4(3/2)) of Er3+ ions. The highest absolute sensitivity was determined as 0.0046 K-1 at 453 K for Er3+ doped glass and 0.0067 K-1 at 353 K for Yb3+/Er3+ co-doped glass. These results show that Er3+ and Yb3+/Er3+ doped TeO2-ZnO-BaO glasses are promising candidates for both lighting and optical temperature sensors.Publication Open Access Spectral investigation of Yb3+/Ho3+/Tm3+:Y2Si2O7 upconverting nanophosphors for the usage of temperature sensing(2023-02-28) ERDEM, MURAT; ESMER, KADİR; ERDEM M., ESMER K., Eryürek G.© 2023, Turkish Chemical Society. All rights reserved.Rare earth (Yb3+, Ho3+, Tm3+) yttrium disilicate phosphors were produced by sol-gel technique and heated at 1050 °C temperature. The sizes of the phosphors vary between 20-30 nm according to the images obtained from the Transmission Electron Microscope. The up-conversion (UC) emissions of the nanopowders were measured in the range of 500–900 nm wavelength under 950 nm laser excitation. A linear increase with power was observed in the emission intensity ratio depending on the laser excitation power. Using the FIR technique, the phosphor’s temperature was determined by the heating effect caused by the laser pump power. Due to the change in intensity ratio versus temperature, the temperature sensitivity at 428 K was calculated as 0.781x10-2K-1 and it was suggested that it can be used as a promising temperature sensor probe in photonic devices.Publication Metadata only Investigation of spectral properties of Er3+/Yb3+ CO-doped TeO2-B2O3-NbO5-ZnO-WO3-TiO2 glass systems(2022-10-04) ERDEM, MURAT; ESMER, KADİR; CANER T. F., Sümer I., Doğan A., ERDEM M., ESMER K., ERYÜREK G.Publication Open Access Spectral outputs of Yb3+/Pr3+ doped tellurite glasses for solid-state lighting(2022-01-01) ERDEM, MURAT; ERDEM M., Doğan A.© 2022, Turkish Chemical Society. All rights reserved.Downconversion processes which include visible and near-infrared luminescence at high energy excitation have been investigated in Yb3+/Pr3+ doped TeO2-ZnO-BaO glasses. The decrease of the DC emission intensities of Pr3+ ions with increasing mol% amount of Pr3+ ions is attributed to the concentration quenching. The CIE chromaticity coordinates of the perceived emission of Pr3+ ions shifted from orange to the red region depending on the increase in the pumping power. Consequently, Yb3+/Pr3+ doped TeO2-ZnO-BaO glasses could be used as functional optical materials for solid-state lighting applications.Publication Metadata only Upconversion Yb3+/Er3+:Gadolinium Gallium Garnet Nanocrystals for White-Light Emission and Optical Thermometry(AMER CHEMICAL SOC, 2021) ERDEM, MURAT; Erdem, Murat; Orucu, Hiimeyra; Canturk, Selim Burak; Eryurek, GoniilThe fabrication of size-dependent rare earth ion-doped materials for photonic devices has attracted interest in the search for color tunability and noncontact temperature sensing properties with high sensitivity. Sol-gel Pechini is an appropriate method compared to other methods to prepare Yb3+/Er3+:gadolinium gallium garnet (GGG) crystals at the nanoscale. This work presents a study of white-light emission and optical thermometry properties of Yb3+/Er3+:GGG nanocrystals based on the upconversion (UC) blue, green, and red emissions observed under 975 nm laser excitation. The color coordinates of the studied nanocrystals were affected by the crystalline size. Yb3+ (2 mol %)/Er3+(1 mol %):GGG nanocrystals have the highest maximum absolute sensitivities of 0.0028 K-1 at 378 K and 0.0041 K-1 at 561 K for 17 and 45 nm crystalline sizes, respectively. In light of the observations, Yb3+/Er3+:GGG may be a good candidate material for use in white light and optical temperature sensing.Publication Metadata only Investigation of the optical temperature sensing properties of up-converting TeO2-ZnO-BaO activated with Yb3+/Tm3+ glasses(ELSEVIER SCIENCE SA, 2021) ERDEM, MURAT; Dogan, Anil; Erdem, MuratThree different tellurite-zinc-barium-based glasses including Yb3+ and Tm3+ ions were fabricated by the conventional melt quenching method. The composition of the glasses are (76-x)% TeO2 + 16 % ZnO + 5% BaO + xTm(2)O(3) + 3% Yb2O3, where x values are 0.075 mol %, 0.15 mol % and 0.3 mol % for Tm3+, respectively. Spectral properties of the powders were detailed to sort out for possible up-conversion (UC) emission mechanism in the range between 400-1700 nm under the wavelength of 975 nm excitation. The optical thermometry properties of the Yb3+/Tm3+: TZB glasses indicated that F-3(4) and H-3(4) levels of the Tm3+ ions have thermally compatible energy pairs at energy ranging Delta E-M which is about 942.1 cm(-1) with the maximum absolute sensitivity of 0.0245 K-1 at 553 K. With these properties, Yb3+/Tm3+: TZB glasses could be a promising candidate for remote temperature sensing in sensor technology. (C) 2021 Elsevier B.V. All rights reserved.Publication Metadata only Synthesis, characterization, third-order non-linear optical properties and DFT studies of novel SUBO bridged ball-type metallophthalocyanines(ROYAL SOC CHEMISTRY, 2020) GÖRK, GÜLŞEN; Alizadeh, Shabnam; Kosoglu, Gulsen; Erdem, Murat; Acar-Selcuki, Nursel; Ozer, Metin; Salih, Bekir; Bekaroglu, OzerNovel 4,4 '-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy)) (SUBO) bridged ball-type metallophthalocyanines were synthesized starting from 4,4 '-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy))diphthalonitrile with convenient metal salts in 2-N,N-dimethylaminoethanol. A new bisphthalonitrile compound was obtained from 2,2 '-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropan-1-ol) and 4-nitrophthalonitrile in acetonitrile at reflux temperature in the presence of potassium carbonate as a catalyst. The structural characterization of the compounds was performed by elemental analysis, and infrared, ultraviolet-visible and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Nonlinear absorptions of the phthalocyanine complexes were measured using the Z-scan technique with 7 ns pulse duration at a 532 nm wavelength. It is obvious that ball-type copperphthalocyanine has a high nonlinear absorption coefficient and imaginary component of the third-order susceptibility compared to other complexes. Therefore, ball-type copperphthalocyanine can be regarded as a very good candidate for optical limiting applications. Density functional theory was used for geometry optimizations and time-dependent density functional theory calculations of electronic transitions in order to compare with the experimental results. Molecular orbital and nonlinear optical analyses were also performed with density functional theory at the CAM-B3LYP/6-31G(d,p)/LANL2DZ level. The nonlinear optical analyses show that ball-type copperphthalocyanine has significantly better nonlinear optical properties in comparison to a common reference compound, urea.