Browsing by Author "Usta, Hakan"
Now showing items 1-20 of 65
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Ambipolar small molecular semiconductor-based heterojunction diode
Ocaya, R. O.; Ozdemir, Mehmet; Ozdemir, Resul; Al-Ghamdi, Ahmed; Usta, Hakan; Farooq, W. A.; Yakuphanoglu, F. (ELSEVIER SCIENCE SAPO BOX 564, 1001 LAUSANNE, SWITZERLAND, 2016)A heterojunction diode based on an ambipolar organic semiconductor 2,8-bis(5-(2-octyldodecyl)thien-2-yl)indeno[1,2-b]fluorene-6,12-dione (20D-TIFDKT) was fabricated on p-Si using a drop-casting technique. The current-voltage ... -
Anhydrous proton conducting poly(vinyl alcohol) (PVA)/ poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS)/1,2,4-triazole composite membrane
Erkartal, Mustafa; Aslan, Ayse; Erkilic, Ufuk; Dadi, Seyma; Yazaydin, Ozgur; Usta, Hakan; Sen, Unal (Elsevier Ltd, 2016)The design and fabrication of anhydrous proton exchange membranes are critically important for high temperature proton exchange membrane fuel cell (HT-PEMFC) operating between 100 and 200 °C. Herein, we demonstrate a novel ... -
Benzotiyeno[3,2-B][1]Benzotiyofen (BTBT) Tabanlı, Yüksek Performanslı N-Tipi/Ambipolar Yarı-İletkenlerin Geliştirilmesi Ve Yüksek Hızda Alan-Etkili Transistör (OFET) Uygulamaları
Usta, Hakan; Demirel, Gökhan (TUBİTAK, 2019)Bu projede, daha önce literatürde bulunmayan, özgün kimyasal yapılara sahip 6 farklı düşük LUMO’lu BTBT-tabanlı yarı-iletken moleküler malzeme quantum mekaniksel hesaplamalarla teorik olarak tasarlanmış ve sentezlenmiştir. ... -
BODIPY-Based Semiconducting Materials for Organic Bulk Heterojunction Photovoltaics and Thin-Film Transistors
Ho, Dongil; Ozdemir, Resul; Kim, Hyungsug; Earmme, Taeshik; Usta, Hakan; Kim, Choongik (WILEY-V C H VERLAG GMBH, POSTFACH 101161, 69451 WEINHEIM, GERMANY, 2019)The rapid emergence of organic (opto)electronics as a promising alternative to conventional (opto)electronics has been achieved through the design and development of novel pi-conjugated systems. Among various semiconducting ... -
Design and development of functional organic small molecules and polymers for optoelectronics
Usta, Hakan; Demirel, Gokhan; Facchetti, Antonio; Muccini, Michele (AMER CHEMICAL SOC1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2016)Design and development of functional organic small molecules and polymers for optoelectronics -
The design and fabrication of supramolecular semiconductor nanowires formed by benzothienobenzothiophene (BTBT)-conjugated peptides
Khalily, Mohammad Aref; Usta, Hakan; Ozdemir, Mehmet; Bakan, Gokhan; Dikecoglu, F.Begum; Gayle, Charlotte Edwards; Hutchinson, Jessica A.; Hamley, Ian W.; Dana, Aykutlu; Guler, Mustafa O. (Royal Society of Chemistry, 2018)?-Conjugated small molecules based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) unit are of great research interest in the development of solution-processable semiconducting materials owing to their excellent charge-transport ... -
Design, synthesis, and characterization of alpha,omega-disubstituted indeno[1,2-b]fluorene-6,12-dione-thiophene molecular semiconductors. Enhancement of ambipolar charge transport through synthetic tailoring of alkyl substituents
Ozdemir, Mehmet; Choi, Donghee; Kwon, Guhyun; Zorlu, Yunus; Kim, Hyekyoung; Kim, Myung-Gil; Seo, SungYong; Sen, Unal; Citir, Murat; Kim, Choongik; Usta, Hakan (ROYAL SOC CHEMISTRYTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2016)A series of indeno[1,2-b]fluorene-6,12-dione-thiophene derivatives with hydrocarbon substituents at alpha,omega-positions as side groups have been designed and synthesized. The new compounds were fully characterized by ... -
Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications
Canlier, Ali; Ucak, Umit Volkan; Usta, Hakan; Cho, Changsoon; Lee, Jung-Yong; Sen, Unal; Citir, Murat (ELSEVIER, 2015)Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Omega/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability ... -
A dopant-free 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT)-based hole transporting layer for highly stable perovskite solar cells with efficiency over 22%
Kaya, Ismail Cihan; Ozdemir, Resul; Usta, Hakan; Sonmezoglu, Savas (ROYAL SOC CHEMISTRY, 2022)In this study, for the first time, n-i-p PSCs were fabricated using dopant-free 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) as the solution-processed hole transporting layer (HTL). The power conversion ... -
Dynamic Tuning of Plasmonic Hot-Spot Generation through Cilia-Inspired Magnetic Actuators
Liman, Gorkem; Ergene, Emre; Yildiz, Emrecan; Hukum, Kubra Ozkan; Huri, Pinar Yilgor; Cetin, Arif E.; Usta, Hakan; Demirel, Gokhan (WILEY, 2023)Soft actuators that draw inspiration from nature are powerful and versatile tools for both technological applications and fundamental research, yet their use in hot-spot engineering is very limited. Conventional hot-spot ... -
Electrochemical polymerization of ambipolar carbonyl-functionalized indenofluorene with memristive properties
Figa, Viviana; Usta, Hakan; Macaluso, Roberto; Salzner, Ulrike; Ozdemir, Mehmet; Kulyk, Bohdan; Krupka, Oksana; Bruno, Maurizio (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2019)Carbonyl-functionalized indenofluorene was electropolymerized with a high faradaic efficiency of 85% and the solid state properties of the resulting polymeric thin films were investigated. They displayed modular optical ... -
Enabling three-dimensional porous architectures via carbonyl functionalization and molecular-specific organic-SERS platforms
Deneme, Ibrahim; Liman, Gorkem; Can, Ayse; Demirel, Gokhan; Usta, Hakan (NATURE RESEARCHHEIDELBERGER PLATZ 3, BERLIN 14197, GERMANY, 2021)Nanostructured films of organic semiconductors with low lying LUMO orbitals can enhance Raman signals via a chemical enhancement mechanism but currently the material choice is limited to fluorinated oligothiophenes. Here, ... -
Engineering functionalized low LUMO [1]benzothieno[3,2-b][1]benzothiophenes (BTBTs): unusual molecular and charge transport properties
Ozdemir, Resul; Ahn, Kyunghan; Deneme, Ibrahim; Zorlu, Yunus; Kim, Dojun; Kim, Myung-Gil; Usta, Hakan (ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2020)Diacene-fused thienothiophenes (DAcTTs) have provided an excellent pi-framework for the development of high mobility p-type molecular semiconductors in the past decade. However, n-type DAcTTs are rare and their electron ... -
Enhanced mass transfer rate and solubility of methane via addition of alcohols for Methylosinus trichosporium OB3b fermentation
Kim, Kwangmin; Kim, Yujin; Yang, Jeongmo; Ha, Kyoung-Su; Usta, Hakan; Lee, Jinwon; Kim, Choongik (ELSEVIER SCIENCE INCSTE 800, 230 PARK AVE, NEW YORK, NY 10169, 2017)The effect of alcohol on methane-water volumetric mass transfer coefficient (1(0) and solubility of methane was investigated in this study. Various alcohols including methanol, ethanol, 1-propanol, butanol, and pentanol ... -
Enhancement of Anhydrous Proton Conductivity of Poly(vinylphosphonic acid)-Poly(2,5-benzimidazole) Membranes via In Situ Polymerization
Sen, Unal; Usta, Hakan; Acar, Oktay; Citir, Murat; Canlier, Ali; Bozkurt, Ayhan; Ata, Ali (WILEY-V C H VERLAG GMBH, 2015)Polymer electrolyte membranes (PEMs) are synthesized via in situ polymerization of vinylphosphonic acid (VPA) within a poly(2,5-benzimidazole) (ABPBI) matrix. The characterization of the membranes is carried out by using ... -
Frequency and electric field controllable photodevice: FYTRONIX device
Tataroglu, A.; Al-Sehemi, Abdullah G.; Ozdemir, Mehmet; Ozdemir, Resul; Usta, Hakan; Al-Ghamdi, Ahmed A.; Farooq, W. A.; Yakuphanoglu, F. (ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2017)Al/p-Si/BODIPY/Al diode was fabricated by forming BODIPY organic layer on p-Si having ohmic contact. The electrical and photoresponse properties of the prepared diode were investigated in detail. The current-voltage ( I-V) ... -
From 2-methylimidazole to 1,2,3-triazole: a topological transformation of ZIF-8 and ZIF-67 by post-synthetic modification
Erkartal, Mustafa; Erkilic, Ufuk; Tam, Benjamin; Yazaydin, Ozgur; Hupp, Joseph T.; Farha, Omar K.; Sen, Unal (ROYAL SOC CHEMISTRYTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2017)Bridging ligand replacement in zeolitic imidazolate frameworks, ZIF-8 and ZIF-67, by 1,2,3-triazole was investigated. A complete substitution of 2-methylimidazole by 1,2,3-triazole resulted in a topological transformation ... -
The Hansen solubility approach towards green solvent processing: n-channel organic field-effect transistors under ambient conditions
Deneme, Ibrahim; Yıldız, Tevhide Ayça; Kayaci, Nilgun; Usta, Hakan (Royal Society of Chemistry, 2024)The adoption of green solvents is of utmost importance for the solution-based fabrication of semiconductor thin films and for the commercialization of (opto)electronic devices, especially in response to evolving regulatory ... -
Hibrit Kuantum Noktacık-Nanofiber Esnek Elektrolüminesant Aygıtlar
Mutlugün, Evren; Usta, Hakan; Önses, Serdar (TUBİTAK, 2019)Yarı iletken kuantum noktacıklar üstün renk dönüşüm özellikleri, yüksek soğurma katsayıları ve kararlılıkları sebebiyle son yıllarda aydınlatma ve ekran teknolojileri için oldukça önemli malzemeler durumundadır. Genel ... -
High Electron Mobility in [1]Benzothieno[3,2-b][1]benzothiophene-Based Field-Effect Transistors: Toward n-Type BTBTs
Usta, Hakan; Kim, Dojeon; Ozdemir, Resul; Zorlu, Yunus; Kim, Sanghyo; Ruiz Delgado, M. Carmen; Harbuzaru, Alexandra; Kim, Seonhyoung; Demirel, Gokhan; Hong, Jongin; Ha, Young-Geun; Cho, Kilwon; Facchetti, Antonio; Kim, Myung-Gil (AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2019)The first example of an n-type [1]benzothieno[3,2-b][1]benzothiophene (BTBT)-based semiconductor, D-(PhFCO)-BTBT, has been realized via a two-step transition metal-free process without using chromatographic purification. ...