Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 8
    Citation - Scopus: 9
    Tuning the Colour of Solution Processed Perylene Tetraester Based Oleds From Yellowish-Green To Greenish-White: a Molecular Engineering Approach
    (Elsevier, 2023) Aksoy, Erkan; Bozkuş, Volkan; Varlıklı, Canan
    Three regioisomericaly pure 1,7-di-ethynyl bridged perylene-3,4,9,10-tetracarboxy tetrabutylesters functionalized with triisopropylsilyl-ethynylen (PTE1), phenyl-ethynylen (PTE2) and tetraphenylsilyl-ethynylen (PTE3) groups were synthesized. Photophysical, thermal, electrochemical, and solution processed electroluminescence (EL) behaviours were investigated in comparison with a basic perylene-3,4,9,10-tetracarboxy tetrabutylester (PTEref) structure. Stepwise π conjugation, allowed tuning the absorption and photoluminescence wavelengths of the PTEs without disturbing the photo, thermal and electrochemical stabilities; ≫10h, >250 °C, and >50 cycles, respectively. Electron mobility of PTE2 is measured to be more than 10-fold of the other PTE derivatives. Individual utilization of PTE derivatives as solid-state emitters in poly(N-vinylcarbazole) (PVK): 2-(4-Biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) host matrix produced yellowish-green EL. Benefiting from higher electron mobiliy, PTE2 emitter presented the best device efficiency values with an EL maximum of 535 nm. Whereas dual doping of the synthesized PTEs with PTEref resulted in greenish-white light with increased stability. Although the emitting layer contained no red emitting component, optimization of the dual doping ratio of PTEref:PTE3 produced a colour rendering index value of 76 with Commission Internationale d'Eclairage coordinates of (0.29, 0.37).
  • 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; Aydın, Hasan; Yağmurcukardeş, Nesli; Demir, Şerafettin; İçli, Sıddık; Okur, Salih
    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: 35
    Citation - Scopus: 37
    Modification of Ito Surface Using Aromatic Small Molecules With Carboxylic Acid Groups for Oled Applications
    (Elsevier Ltd., 2011) Havare, Ali Kemal; Can, Mustafa; Demiç, Şerafettin; Okur, Salih; Kuş, Mahmut; Aydın, Hasan; Yağmurcukardeş, Nesli; Tarı, Süleyman
    4-[(3-Methylphenyl)(phenyl)amino]benzoic acid (MPPBA) was synthesized in order to facilitate the hole-injection in Organic Light Emitting Diodes (OLED). MPPBA was applied to form self-assembled monolayer (SAM) on indium tin oxide (ITO) anode to align energy-level at the interface between organic semiconductor material (TPD) and inorganic anode (ITO) in OLED devices. The modified surface was characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). KPFM was used to measure the surface potential and work function between the tip and the ITO surface modified by SAM technique using MPPBA. The OLED devices (ITO/MPPBA/TPD/Alq3/Al) fabricated with SAM-modified ITO substrates showed lower turn-on voltages and enhanced diode current compare to the OLED devices fabricated with bare ITO substrates.