Department of Physics
Recent Submissions
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Many-body effects in a two-component, one-dimensional electron gas with repulsive, short-range interactions
(Elsevier, 1998-03-09)We investigate the correlation effects in a two-component, one-dimensional electron gas interacting via repulsive δ function interactions. Electron correlations are treated within the approximation scheme of Singwi, Tosi, ... -
Formation of silicon nanocrystals in sapphire by ion implantation and the origin of visible photoluminescence
(AIP Publishing, 2006)Silicon nanocrystals, average sizes ranging between 3 and 7 nm, were formed in sapphire matrix by ion implantation and subsequent annealing. Evolution of the nanocrystals was detected by Raman spectroscopy and x-ray ... -
Probing Voltage Drop Variations in Graphene with Photoelectron Spectrosopy
(American Chemical Society, 2013)We use X-ray photoelectron spectroscopy (XPS) for characterization of voltage drop variations of large area single-layer graphene on quartz substrates, by application of a voltage bias across two gold electrodes deposited ... -
Room temperature magnetic imaging of magnetic storage media and garnet epilayers in the presence of external magnetic fields using a sub-micron GaAs SHPM
(Elsevier, 2001-07)A multipurpose room temperature scanning Hall probe microscope (RT-SHPM) system incorporating an ultra-high sensitive sub-micron GaAs Hall probe (active area of similar to0.8 x 0.8 mum(2) room temperature Hall coefficient ... -
Energy transfer rate in Coulomb coupled quantum wires
(American Institute of Physics, 1997)We study the energy transfer rate for electrons in two parallel quantum wires due to interwire Coulomb interactions. The energy transfer rate between the wires (similar to the Coulomb drag effect in which momentum transfer ... -
Formation of Ge nanocrystals and SiGe in PECVD grown SiNx:Ge thin films
(Elsevier, 2006)ormation of Ge nanocrystals in SiNx matrices has been studied using plasma enhanced chemical vapor deposition in both as deposited samples as well as in post-vacuum annealed samples. Low temperature and short duration ... -
100 GHz resonant cavity enhanced Schottky photodiodes
(IEEE, 1998-05)Resonant cavity enhanced (RCE) photodiodes are promising candidates for applications in optical communications and interconnects where ultrafast high-efficiency detection is desirable. We have designed and fabricated RCE ... -
Prism coupling technique investigation of elasto-optical properties of thin polymer films
(American Institute of Physics, 2004)The use of thin polymer films in optical planar integrated optical circuits is rapidly increasing. Much interest, therefore, has been devoted to characterizing the optical and mechanical properties of thin polymer films. ... -
A Comparative Passivation Study for InAs/GaSb Pin Superlattice Photodetectors
(IEEE, 2013-08)In the quest to find ever better passivation techniques for infrared photodetectors, we explore several passivation layers using atomic layer deposition (ALD). We compare the impact of these layers on detectors fabricated ... -
Effects of static charging and exfoliation of layered crystals
(American Physical Society, 2012-01-20)We demonstrate that graphene coating can provide efficient protection from oxidation by posing a high-energy barrier to the path of oxygen atom, which could have penetrated from the top of the graphene to the reactive ... -
Enhancement of optical switching parameter and third-order optical nonlinearities in embedded Si nanocrystals: A Theoretical Assessment
(Elsevier, 2008-08)Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide bandgap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive ... -
Gain and temporal response of A1GaN solar-blind avalanche photodiodes: An essemble Monte Carlo analysis
(American Institute of Physics, 2003)Multiplication and temporal response characteristics of p(+)-n-n(+) GaN and n-type Schottky Al0.4Ga0.6N avalanche photodiodes (APD) have been analyzed using the ensemble Monte Carlo method. Reasonable agreement is obtained ... -
Excited-state dynamics and nonlinear optical response of Ge nanocystals embedded in silica matrix
(A I P Publishing LLC, 2006-05-01)We use a dedicated Z-scan setup, arranged to account for cumulative effects, to study the nonlinear optical response of Ge nanocrystals embedded in silica matrix. Samples are prepared with plasma-enchanced chemical-vapor ... -
Electronic structure of the contact between carbon nanotube and metal electrodes
(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 ... -
Microjoule-energy, 1 MHz repetition rate pulses from all-fiber-integrated nonlinear chirped-pulse amplifier
(Optical Society of America, 2010-03-23)We demonstrate generation of pulses with up to 4 mu J energy at 1 MHz repetition rate through nonlinear chirped-pulse amplification in an entirely fiber-integrated amplifier, seeded by a fiber oscillator. The peak power ... -
Polymeric waveguide Bragg grating filter using soft lithography
(Optical Society of America, 2006)We use the soft lithography technique to fabricate a polymeric waveguide Bragg grating filter. Master grating structure is patterned by e-beam lithography. Using an elastomeric stamp and capillary action, uniform grating ... -
Peptide-Mediated Constructs of Quantum Dot Nanocomposites for Enzymatic Control of Nonradiative Energy Transfer
(American Chemical Society, 2011-03-23)A bottom-up approach for constructing colloidal semiconductor quantum dot (QDot) nanocomposites that facilitate nonradiative Forster-type resonance energy transfer (FRET) using polyelectrolyte peptides was proposed and ... -
Local Reconstructions of Silicene Induced by Adatoms
(American Chemical Society, 2013-11-25)The interaction of silicene with Si, C, H, O, and Ti atoms along with H-2, H2O, and O-2 molecules are investigated and the induced functionalities thereof are analyzed using first principles density functional theory. Si ... -
Range-Separated Hybrid Density Functional Study of Organic Dye Sensitizers on Anatase TiO2 Nanowires
(American Chemical Society, 2014-09-30)The adsorption of organic molecules coumarin and the donor-p-acceptor type tetrahydroquinoline (C2-1) on anatase (101) and (001) nanowires has been investigated using screened Coulomb hybrid density functional theory ... -
Non-covalent functionalization of single wall carbon nanotubes and graphene by a conjugated polymer
(AIP Publishing, 2014-07-07)We report first-principles calculations on the binding of poly[(9,9-bis-(6-bromohexylfluorene-2,7-diyl)-co-(benzene-1,4-diyl)] to a (8,0) single wall carbon nanotube (SWCNT) and to graphene. Considering different relative ...
