Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Article Citation - WoS: 3Citation - Scopus: 3Synthesis and Raman Spectroscopic Investigation of a New Self-Assembly Monolayer Material 4-[n Acid for Organic Light-Emitting Devices(John Wiley and Sons Inc., 2011) Kurt, Mustafa; Okur, Salih; Demiç, Şerafettin; Karpagam, J.; Sundaraganesan, N.We have synthesized 4-[N-phenyl-N-(3-methylphenyl)-amino]-benzoic acid (4-[PBA]) and investigated its molecular vibrations by infrared and Raman spectroscopies as well as by calculations based on the density functional theory (DFT) approach. The Fourier transform (FT) Raman, dispersive Raman and FT-IR spectra of 4-[PBA] were recorded in the solid phase. We analyzed the optimized geometric structure and energies of 4-[PBA] in the ground state. Stability of the molecule arising from hyperconjugative interactions and charge delocalization was studied using natural bond orbital analysis. The results show that change in electron density in the δ* and π* antibonding orbitals and E 2 energies confirm the occurrence of intramolecular charge transfer within the molecule. Theoretical calculations were performed at the DFT level using the Gaussian 09 program. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compound, which show agreement with the observed spectra.Article Citation - WoS: 35Citation - Scopus: 37Modification 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, Süleyman4-[(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.
