Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 271Citation - Scopus: 279Nanostructured Organic Semiconductor Films for Molecular Detection With Surface-Enhanced Raman Spectroscopy(Nature Publishing Group, 2017-08-07) Yilmaz, Mehmet; Babur, Esra; Ozdemir, Mehmet; Gieseking, Rebecca L.; Dede, Yavuz; Tamer, Ugur; Demirel, Gokhanpi-Conjugated organic semiconductors have been explored in several optoelectronic devices, yet their use in molecular detection as surface-enhanced Raman spectroscopy (SERS)-active platforms is unknown. Herein, we demonstrate that SERS-active, superhydrophobic and ivy-like nanostructured films of a molecular semiconductor, alpha,omega-diperfluorohexylquaterthiophene (DFH-4T), can be easily fabricated by vapour deposition. DFH-4T films without any additional plasmonic layer exhibit unprecedented Raman signal enhancements up to 3.4 x 10(3) for the probe molecule methylene blue. The combination of quantum mechanical computations, comparative experiments with a fluorocarbon-free alpha,omega-dihexylquaterthiophene (DH-4T), and thin-film microstructural analysis demonstrates the fundamental roles of the pi-conjugated core fluorocarbon substitution and the unique DFH-4T film morphology governing the SERS response. Furthermore, Raman signal enhancements up to similar to 10(10) and sub-zeptomole (< 10(-21) mole) analyte detection were accomplished by coating the DFH-4T films with a thin gold layer. Our results offer important guidance for the molecular design of SERS-active organic semiconductors and easily fabricable SERS platforms for ultrasensitive trace analysis.Article Citation - WoS: 7Citation - Scopus: 7Atomic Structure of Amorphous CDO from First Principles Simulations(Elsevier Science Bv, 2015-03) Durandurdu, MuratAmorphous CdO (a-CdO) is obtained by cooling the liquid at a sufficiently fast cooling rate using first-principles simulations. The topology of the amorphous model is examined using a variety of analyzing techniques. The local structural arrangement of a-CdO is found to be partially similar to that of crystalline phase. The model is chemically ordered but consists of a significant amount of coordination defects. a-CdO is predicted to be a semiconductor with a band gap energy less than the crystalline state. It is likely that a-CdO might serve as a novel electronic material. (C) 2015 Elsevier B.V. All rights reserved.