Browsing by Author "Kiremitler, Nuri Burak"

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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) 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;Hpi 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.
Citation - WoS: 15
Citation - Scopus: 18
FRET Enabled Light Harvesting within Quantum Dot Loaded Nanofibers
(IOP Publishing Ltd, 2018) Altintas, Yemliha; Kiremitler, Nuri Burak; Genc, Sinan; Onses, M. Serdar; Mutlugun, Evren
The spatial control of the nano-emitters in novel light harvesting platforms offers great potential for the manipulation of the excitonic interaction amongst the donor-acceptor pairs of energy transferring agents. In this work, we report colloidal quantum dot loaded electrospun nanofibers as a light harvesting platform to study the excitonic interaction among them. The donor emission lifetime modified from 12.46 ns to 7.45 ns with the change in the ratio of green and red quantum dots in the nanofiber, as a result of confining acceptor quantum dots in close proximity. The spectrally narrow emitter luminescent nanofiber platforms have further been investigated for their potential of white light generation. The hybrid platform of blue LED integrated electrospun nanofibers has been shown to demonstrate a correlated color temperature of 3632.5 K, luminous efficacy of optical radiation value of 307.7 lm/W-opt along with color rendering index value of 60.