Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

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

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Subject: search.filters.subject.Solution processed OLEDWoS Q: search.filters.wosQuartile.Q1

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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: 14
    Citation - Scopus: 14
    Dispersion Stability of Amine Modified Graphene Oxides and Their Utilization in Solution Processed Blue Oled
    (Elsevier Ltd., 2020) Diker, Halide; Bozkurt, Hakan; Varlıklı, Canan
    Graphene oxide (GO) was modified with amine derivatives which contain short (SACA) and long (LACA) alkyl chains. SACAs were n-propylamine, dipropylamine, propanolamine and LACAs were 2-ethylhexylamine, di-hexylamine, dioctylamine, and 1,12-diaminododecane and modified GOs (mGOs) were named as nPRYLA-GO, DPRYLA-GO, PRPOHA-GO, 2EHA-GO, DHA-GO, DOA-GO, and DADOD-GO, respectively. Amine modification resulted in approximately 2-folds of decrement in d-spacing of GO (8.36 angstrom). The C:O ratio, N% and d-spacing values were increased as the alkyl chain length of amine source increased. Except for PRPOHA-GO, all of the mGOs were thermally stable until 100 degrees C. All mGOs were dispersed in dimethylformamide (DMF), ethylene glycol (EG) and isopropyl alcohol (iPA). Regardless of their structural differences, all of the mGOs formed stable dispersions in DMF, whereas SACA-mGOs and LACA-mGOs were compatible with EG and iPA, respectively. DMF, EG and iPA dispersions of DOA-GO, 2EHA-GO, nPRYLA-GO and PRPOHA-GO were doped in Al4083 and prepared composites were utilized as hole transport layer in solution processed blue OLEDs. Ground state energy levels of Al4083:DOA-GO, Al4083:EG, Al4083:PRPOHA-GO, Al4083:2EHA-GO and Al4083:nPRYLA-GO extracted from their X-ray photoelectron spectra were 0.49 eV, 0.67 eV, 0.91 eV, 0.98 eV and 1.00 eV below the work function of ITO, respectively. Among all Al4083:mGOs, the best device performance was obtained with the device that contains Al4083:DOA-GO (in EG), which presented 1.6, 1.7 and 1.5 fold enhancements in current, power and external quantum efficiencies, respectively, compared to those of Al4083:EG based device.