WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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Author: search.filters.author.Usta, HakanHas files: No

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Now showing 1 - 10 of 10
  • Conference Object
    Thin Films of Inert Metal Nanowires for Display Applications
    (Tanger Ltd, 2015) Citir, Murat; Sen, Unal; Usta, Hakan; Canlier, Ali; Hakan, Usta; Ali, Canlier; Murat, Citir; Unal, Sen
    Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Ohm/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. Coating Ag nanowires with a thin layer of inert metals such as Au and Pd through galvanic exchange reactions may enhance the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of thin Au and Pd layers has been applied successfully onto the surface of Ag nanowires. Usually coatings are carried out by salts such as HAuCl4 and K2PdCl4 in order to make nanotubes. In this study, novel ethylenediamine(en) complexes of inert metal cations with mild oxidation power were prepared in order to oxidize Ag atoms partially on the surface through galvanic displacement. The mild galvanic exchange allowed for a thin layer (1-4 nm) of inert metal coating on the Ag nanowires with minimal truncation of the nanowire, where the average lengths and the diameters were between 10 similar to 14 mu m and 55 similar to 65 nm, respectively. The crystalline structure of the shell was formed epitaxially on the surface. The new Ag nanowires were suspended in methanol and then electrostatically sprayed on glass and flexible substrates. It was revealed that average total transmittance remain around 90% within visible spectrum region (400-800 nm) whereas sheet resistance rises up to 175 Ohm/sq. Very thin layer of inert metal costs low, though this may render an excellent catalyst for applications such as fuel cell and organic synthesis, whereas transparent films of inert metal-coated Ag nanowire can be utilized as working electrodes for spectro-electrochemical cells as well.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Stochastic Orientational Encoding via Hydrogen Bonding Driven Assembly of Woven-Like Molecular Physically Unclonable Functions
    (Wiley-VCH Verlag GmbH, 2025-07-02) Kayaci, Nilgun; Kiremitler, Nuri Burak; Deneme, Ibrahim; Kalay, Mustafa; Ozbasaran, Aleyna; Zorlu, Yunus; Usta, Hakan
    The prevention of counterfeiting and the assurance of object authenticity require stochastic encoding schemes based on physically unclonable functions (PUFs). There is an urgent need for exceptionally large encoding capacities and multi-level responses within a molecularly defined, single-material system. Herein, a novel stochastic orientational encoding approach is demonstrated using a facile ambient-atmosphere solution processing of a molecular thin film based on the rod-shaped oligo(p-phenyleneethynylene) (OPE) pi-architecture. The nanoscopic film, derived from the small molecule 2EHO-CF3PyPE with donor, acceptor, and pi-spacer building units, is designed for energetically favorable uniaxial molecular assembly and crystal growth via directional multiple hydrogen-bonding motifs at the molecular termini and short C & horbar;H<middle dot><middle dot><middle dot>pi contacts at the center. A facile solvent vapor annealing induces concurrent dewetting and microscopic 1D random crystallization, yielding a woven-textured random features. Using convolutional neural networks, the rich variations in microcrystal domain properties and stochastic encoding of 1D crystal orientations generate artificial coloration, achieving an encoding capacity reaching (6.5 x 10(4))(2752 x 2208). The results demonstrate an effective strategy for achieving ultrahigh encoding capacities in a thin film composed of a single-material. This approach enables low-cost, solution-processed fabrication for mass production and broad adoption, while opening new opportunities to explore molecular-PUFs through structural design and engineering noncovalent interactions.
  • Conference Object
    Polymeric Semiconductors Based on Meso-Substituted BODIPY for (Opto)electronic Applications
    (Amer Chemical Soc, 2019) Usta, Hakan; Kim, Choongik; Kim, Bumjoon
  • Conference Object
    Photophysical Properties of Self-Assembled Supramolecular Peptide Nanofiber Organic Semiconductors
    (Amer Chemical Soc, 2015) Khalily, Mohammad Aref; Usta, Hakan; Guler, Mustafa O.
  • Conference Object
    Organic Semiconductor Based Surface-Enhanced Raman Spectroscopy Platforms
    (Amer Chemical Soc, 2018) Demirel, Gokhan; Usta, Hakan; Facchetti, Antonio
  • Conference Object
    Novel Photothermal-Based Release Mechanism for Controlled Release on Au Nanoparticles Through Light
    (Amer Chemical Soc, 2015) Goren, Ekrem; Cavusoglu, Halit; Yavuz, Emine; Usta, Hakan; Yavuz, Mustafa Selman
  • Correction
    Citation - WoS: 1
    Naphthalene Diimide-Based Polymeric Semiconductors. Effect of Chlorine Incorporation and N-Channel Transistors Operating in Water-Corrigendum
    (Cambridge Univ Press, 2016-03) Ryu, Gi-Seong; Chen, Zhihua; Usta, Hakan; Noh, Yong-Young; Fachetti, Antonio; Fabiano, Simone
  • Conference Object
  • Conference Object
    Design and Development of Functional Organic Small Molecules and Polymers for Optoelectronics
    (Amer Chemical Soc, 2016) Usta, Hakan; Demirel, Gokhan; Facchetti, Antonio; Muccini, Michele
  • Conference Object
    Novel Method Based on Photothermal Cleavage of Thermolabile Molecules on Au Nanoparticles for Controlled Release
    (Amer Chemical Soc, 2016) Goren, Ekrem; Cavusoglu, Halit; Yavuz, Emine; Usta, Hakan; Citir, Murat; Yavuz, Mustafa Selman