Browsing by Author "Kocabaş, Coşkun"
Now showing items 21-39 of 39
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High-frequency performance of submicrometer transistors that use aligned arrays of single-walled carbon nanotubes
(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) ... -
Hybrid J-Aggregate–graphene phototransistor
(American Chemical Society, 2020)J-aggregates are fantastic self-assembled chromophores with a very narrow and extremely sharp absorbance band in the visible and near-infrared spectrum, and hence they have found many exciting applications in nonlinear ... -
Integrated optical displacement sensors for scanning force microscopies
(Bilkent University, 2003)In this thesis, we have studied the use of integrated optical waveguide devices acting as integrated displacement sensors on cantilevers for scanning probe microscopes. These displacement sensors include integrated optical ... -
Investigation of the ultrafast response and saturable absorption of voltage-controlled graphene
(OSA, 2018)Ultrafast pump-probe measurements show that at a bias voltage of 1V, voltage reconfigurable graphene supercapacitors can operate as fast saturable absorbers with adjustable insertion loss over an ultrabroad spectral range ... -
Large Rabi splitting of mixed plasmon–exciton states in small plasmonic moire cavities
(OSA - The Optical Society, 2020)We report on exciton–plasmon coupling in metallic moire cavities, both numerically and experimentally. Moire cavities fabricated using double exposure laser interference lithography were filled with a molecular dye, ... -
Localization of surface plasmon polaritons in hexagonal arrays of Moiré cavities
(AIP Publishing, 2011-01)In view of the progress on the confinement of light, we report on the dispersion characteristics of surface plasmon polaritons (SPPs) on two-dimensional Moire surfaces in the visible part of the electromagnetic spectrum. ... -
Modulation behaviors, conductivities, and carrier dynamics of single and multilayer graphenes
(IEEE Computer Society, 2019)Time domain and time resolved terahertz studies of single- and multi-layer graphene (SLG and MLG) samples and modulator devices will be presented. A high performance up to 100% of modulators were observed with the devices ... -
Molecular scale buckling mechanics in individual aligned single-wall carbon nanotubes on elastomeric substrates
(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 ... -
Nonlinear equivalent circuit model for circular CMUTs in uncollapsed and collapsed mode
(IEEE, 2012)An equivalent electrical circuit model valid for collapsed mode operation of CMUT is described. The across and through variables of the circuit model are chosen to be rms force and rms displacement over the surface of the ... -
Novel integrated optical displacement sensor for scanning force microscopies
(IEEE, 2003)A novel displacement sensor for scanning force microscoples using an integrated optical micro-ring resonator is described. Device operates by monitoring the changes in transmission spectrum of micro-ring resonator. This ... -
Passivation of type II InAs / GaSb superlattice photodetectors with atomic layer deposited Al2O3
(SPIE, 2012)We have achieved significant improvement in the electrical performance of the InAs/GaSb midwave infrared photodetector (MWIR) by using atomic layer deposited (ALD) aluminium oxide (Al2O3) as a passivation layer. Plasma free ... -
Pressure sensing using micromachined asymmetric integrated vertical coupler
(IEEE, 2003)Analysis of a novel pressure sensor based on a SOI asymmetric vertical coupler is presented. The integrated optical component is a coupler composed of a single mode low index waveguide and a thin silicon slab. -
Printed multilayer superstructures of aligned single-walled carbon nanotubes for electronic applications
(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 ... -
Slow plasmons in grating cavities
(SPIE, 2016)Recent research on surface plasmon polaritons and their applications have brought forward a wealth of information and continues to be of interest to many. In this report, we concentrate on propagating surface plasmon ... -
Slowing surface plasmon polaritons on plasmonic coupled cavities by tuning grating grooves
(American Institute of Physics, 2010-09)We investigate slow surface plasmon polaritons (SPPs) in plasmonic waveguiding bands formed by coupled plasmonic cavities on Moiŕ surfaces. We demonstrate controlling the group velocity and dispersion of the SPPs by varying ... -
Synthesis of graphene on ultra-smooth copper foils for large area flexible electronics
(IEEE, 2015)This work demonstrates the synthesis of high quality, single layer graphene on commercially available ultra-smooth copper foils. The presented method will result in improved scalability of graphene based electronic and ... -
Ultra-lightweight Chemical Vapor Deposition grown multilayered graphene coatings on paper separator as interlayer in lithium-sulfur batteries
(Elsevier, 2019)Lithium-Sulfur (Li-S) batteries are known for their high energy density and cost-effectiveness. However, the Li-S chemistry is a challenging topic due to the shuttle effect and the use of highly reactive lithium metal ... -
Ultrafast spectroscopy of voltage reconfigurable graphene saturable absorbers in the visible and near infrared
(IOP, 2019-04-23)We describe a detailed experimental investigation of the ultrafast nonlinear response of a voltagecontrolled graphene-gold saturable absorber (VCG-gold-SA) by employing femtosecond pump probe spectroscopy. Visible and ... -
XPS investigation of the vacuum interface of an ionic liquid under triangular electrical excitation for slow transients
(Royal Society of Chemistry, 2018)We report on an XPS investigation of slow transient charge imbalance at the vacuum interface of an ionic liquid, by imposing a triangular electrical excitation to two gold electrodes having an ionic liquid in between. ...
