WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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  • Article
    Citation - WoS: 1
    Investigation of the Electrical Parameters of the Organic Diode Modified With 4-[(3 Benzoic Acid
    (Electrochemical Society, Inc., 2016) Havare, A. Kemal; Okur, Salih; Can, Mustafa; Yağmurcukardeş, Nesli; Yiğit, Mesude Zeliha; Aydın, Hasan; Okur, Salih; Demiç, Şerafettin; İçli, Sıddık; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    4-[(3-Methylphenyl)(phenyl)amino]benzoic acid (MPPBA) self-assembled monolayer (SAM) molecules as hole injection is formed on p and n type Si and on indium-tin oxide (ITO) electrodes to investigate the effect on the electrical parameters of hole only organic device. The hole mobility improvement of organic device was attributed to an intermediate energy level formed between hole transport materials (HTL) (N,N'-Bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine -NPB) and ITO when forming an ultrathin MPPBA layer, leading to increase of carrier mobility of the device. Space charge limited current (SCLC) technique is used to estimate the mobility of the NPB formed at the interface metal/organic Ohmic contact. The hole mobility of ITO/NPB/Al and ITO/MPPBA/NPB/Al devices were obtained as 1.80 x 10(-6) and 1.76 x 10(-3) cm(2)/Vs, at 1350 E (V/cm)(1/2) applied electric field, respectively. SAM modified devices has lower barrier height values. The electronic characteristic parameters of the ITO/(with or without MPPBA)/NPB/Al, Au/n-Si(or p-Si)/(with or without MPPBA)/Au contacts were calculated using current-voltage (I-V) measurements by Schottky type carrier injection. (C) The Author(s) 2016. Published by ECS.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 31
    Electrical Properties of Sam-Modified Ito Surface Using Aromatic Small Molecules With Double Bond Carboxylic Acid Groups for Oled Applications
    (Elsevier Ltd., 2014) Can, Mustafa; Havare, Ali Kemal; Okur, Salih; Yağmurcukardeş, Nesli; Demir, Şerafettin; İçli, Sıddık; Okur, Salih; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space-charge-limited current measurements (SCLC).
  • Article
    Citation - WoS: 32
    Citation - Scopus: 32
    Optical and Electrochemical Properties of Polyether Derivatives of Perylenediimides Adsorbed on Nanocrystalline Metal Oxide Films
    (Elsevier Ltd., 2013) Kuş, Mahmut; Varlıklı, Canan; Özçelik, Serdar; Varlıklı, Canan; Demiç, Şerafettin; Özçelik, Serdar; İçli, Sıddık; 04.01. Department of Chemistry; 04.04. Department of Photonics; 04. Faculty of Science; 01. Izmir Institute of Technology
    We report optical and electrochemical properties of polyether derivatives of perylenediimides (PDIs) thin films formed in various materials (semiconductor, insulator, amorphous and self-assembly). Perylenediimides adsorbed on nanocrystalline TiO2(NT) nanocrystalline alumina (NA), amorphous silicon (PS) and neat self-assemblied (SA) films were prepared and characterized based on spectroscopic, electrochemical, spectro-electrochemical techniques. The absorption and fluorescence spectra of PDIs in chloroform exhibit vibronic features. The fluorescence quantum yields (Uf) of PDIs with end amino substituents in chloroform solutions are over 0.95, while the quantum yield of triethoxyphenyl substituted PDIUfvalue is 0.024 in solution. Optical spectroscopy proves that PDIs in metal oxide thin films form aggregated type complexes. An electrochromism, a color change from red to blue/violet, is observed on metal oxide films, that indicates existence of mono and dianion forms of PDIs. Reversibility of electrochemical reductions in NT film depends on the scanning rate. However, electrochromism in NA films is stable and reversibility is independent from scanning rate. Stable mono and diaionic species are formed on NA films. SA films show broad absorption peaks during the voltammetric scan. On the other hand, the first reduction onset potentials of PDIs are almost equal to the onset potential of capacitive current of TiO2which lead to low efficiency in dye-sensitized solar cells.