Now showing items 1-19 of 19

    • Ab-initio electron transport calculations of carbon based string structures 

      Tongay, S.; Senger, R. T.; Dag, S.; Çıracı, Salim (American Physical Society, 2004)
      The new stable structures of carbon-based strings and their unusual electronic transport properties were discussed. Total energy and electronic structure calculations using first principles pseudopotential plane wave method ...
    • Alignment controlled growth of single-walled carbon nanotubes on quartz substrates 

      Xiao, J.; Dunham, S.; Liu, P.; Zhang, Y.; Kocabaş, Coşkun; Moh, L.; Huang, Y.; Hwang, K. -C.; Lu, C.; Huang, W.; Rogers, J. A. (American Chemical Society, 2009-09-11)
      Single-walled carbon nanotubes (SWNTs) possess extraordinary electrical properties, with many possible applications in electronics. Dense, horizonally aligned arrays of linearly configured SWNTs represent perhaps the most ...
    • All-fiber Yb-doped laser mode-locked by nanotubes 

      Zhang, Zewang; Popa, D.; Sun, Z.; Hasan, T.; Ferrari, A.C.; İlday, F. Ömer (IEEE, 2013)
      Single-wall carbon nanotubes (SWNTs) and graphene have emerged as promising saturable absorbers (SAs), due to their broad operation bandwidth and fast recovery times [1-3]. However, Yb-doped fiber lasers mode-locked using ...
    • Atomic strings of group IV, III-V, and II-VI elements 

      Tongay, S.; Durgun, Engin; Çıracı, Salim (American Institute of Physics, 2004)
      A systematic first-principles study of atomic strings made by group IV, III-V, and II-VI elements has revealed interesting mechanical, electronic, and transport properties. The double bond structure underlies their unusual ...
    • Chemically specific dynamic characterization of photovoltaic and photoconductivity effects of surface nanostructures 

      Ekiz, O. Ö.; Mizrak, K.; Dâna, A. (American Chemical Society, 2010)
      We report characterization of photovoltaic and photoconductivity effects on nanostructured surfaces through light induced changes in the X-ray photoelectron spectra (XPS). The technique combines the chemical specificity ...
    • Chiral single-wall gold nanotubes 

      Senger, R. T.; Dag, S.; Çıracı, Salim (American Physical Society, 2004)
      The formation of freestanding and tip-suspended chiral-wall (n,m) nanotubes, which were composed of helical atomic strands, from gold atoms was investigated using first-principles calculations, where (n,m) notation defines ...
    • DFT studies of CNT-functionalized uracil-acetate hybrids 

      Mirzaei, M.; Gulseren, O. (Elsevier, 2015)
      Calculations based on density functional theory (DFT) have been performed to investigate the stabilities and properties of hybrid structures consisting of a molecular carbon nanotube (CNT) and uracil acetate (UA) counterparts. ...
    • Electronic structure of the contact between carbon nanotube and metal electrodes 

      Dag, S.; Gülseren, O.; Çıracı, Salim; Yildirim, T. (American Institute of Physics, 2003)
      Our first-principles study of the contact between a semiconducting single-walled carbon nanotube ~s-SWNT! and metal electrodes shows that the electronic structure and potential depend strongly on the type of metal. The ...
    • Energetics and Electronic Structures of Individual Atoms Adsorbed on Carbon Nanotubes 

      Durgun, Engin; Dag, S.; Çıracı, Salim; Gülseren, O. (American Chemical Society, 2004)
      The adsorption of individual atoms on the semiconducting and metallic single-walled carbon nanotubes (SWNT) has been investigated by using the first principles pseudopotential plane wave method within density functional ...
    • Functionalized carbon nanotubes and device applications 

      Çıracı, Salim; Dağ, Sefa; Yıldırım, T.; Gülseren, Oğuz; Senger, Ramazan Tuğrul (IOP, 2004)
      Carbon nanotubes, in which the two-dimensional hexagonal lattice of graphene is transformed into a quasi-one-dimensional lattice by conserving the local bond arrangement, provide several structural parameters for engineering ...
    • High-frequency performance of submicrometer transistors that use aligned arrays of single-walled carbon nanotubes 

      Kocabaş, Coşkun; Dunham, S.; Cao, Q.; Cimino, K.; Ho, X.; Kim, H.-S.; Dawson, D.; Payne, J.; Stuenkel, M.; Zhang, H.; Banks, T.; Feng, M.; Rotkin, S. V.; Rogers, J. A. (American Chemical Society, 2009-04-08)
      The unique electronic properties of single-walled carbon nanotubes (SWNTs) make them promising candidates for next generation electronics, particularly in systems that demand high frequency (e.g., radio frequency, RF) ...
    • Intimate relationship between structural deformation and properties of single-walled carbon nanotubes 

      Yıldırım, Taner; Gülseren, Oğuz; Çıracı, Salim (Cambridge, 2002)
      Carbon nanotubes continue to surprise scientists with their novel properties. Recently we have discovered many intimate relationships between structural deformation and the properties of single-walled nanotubes (SWNT), ...
    • Molecular scale buckling mechanics in individual aligned single-wall carbon nanotubes on elastomeric substrates 

      Khang, D. -Y.; Xiao, J.; Kocabaş, Coşkun; MacLaren, S.; Banks, T.; Jiang, H.; Huang, Y. Y.; Rogers, J. A. (American Chemical Society, 2008)
      We have studied the scaling of controlled nonlinear buckling processes in materials with dimensions in the molecular range (i.e., ∼1 nm) through experimental and theoretical studies of buckling in individual single-wall ...
    • Operation of carbon nanotube thin-film transistors at elevated temperatures 

      Öztürk, Sadi; Doğan, Mustafa; Aktaş, Özgür (IEEE, 2009-12)
      The authors study the operation of carbon nanotube thin-film transistors (CNT-TFT) at elevated temperatures. Due to the small bandgap of semiconducting carbon nanotubes, CNT-TFTs are not suitable to be developed as ...
    • Printed multilayer superstructures of aligned single-walled carbon nanotubes for electronic applications 

      Kang, S. J.; Kocabaş, Coşkun; Kim, H.-S.; Cao, Q.; Meitl, M. A.; Khang, D.-Y.; Rogers, J. A. (American Chemical Society, 2007-10)
      We developed means to form multilayer superstructures of large collections of single-walled carbon nanotubes (SWNTs) configured in horizontally aligned arrays, random networks, and complex geometries of arrays and networks ...
    • Quantum effects in electrical and thermal transport through nanowires 

      Çıracı, Salim; Buldum, A.; Batra, I. P. (Institute of Physics Publishing, 2001)
      Nanowires, point contacts and metallic single-wall carbon nanotubes are one-dimensional nanostructures which display important size-dependent quantum effects. Quantization due to the transverse confinement and resultant ...
    • Structural and electronic properties of carbon-based materials 

      Kılıç, Çetin (Bilkent University, 2000)
      In this thesis, some carbon-based materials in nano scale have been investigated by using first-principles methods as well as transferable tight-binding and empirical potential models. The focus of interest has been in ...
    • Titanium-decorated carbon nanotubes as a potential high-capacity hydrogen storage medium 

      Yildirim, T.; Çıracı, Salim (American Physical Society, 2005)
      We report a first-principles study, which demonstrates that a single Ti atom coated on a single-walled nanotube (SWNT) binds up to four hydrogen molecules. The first H2 adsorption is dissociative with no energy barrier ...
    • Use of saccharides as solid-state precursors for the synthesis of carbon nanotubes 

      Küçükkayan, Gökçe; Kayacan, Serim; Baykal, Beril; Bengu, Erman (Materials Research Society, 2008)
      Saccharides, ranging from simple table sugar (sucrose) to lactulose were successfully used as solid-state precursors for the synthesis of multi-walled carbon nanotubes (MWCNT). Dehydrated saccharide residues mixed with ...