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Device For Detailed Analysis Of Leakage Current Paths In Photovoltaic Modules Under High Voltage Bias, Neelkanth G. Dhere, Narendra S. Shiradkar, Eric Schneller
Device For Detailed Analysis Of Leakage Current Paths In Photovoltaic Modules Under High Voltage Bias, Neelkanth G. Dhere, Narendra S. Shiradkar, Eric Schneller
Faculty Bibliography 2010s
High voltages used in photovoltaic (PV) systems are known to induce long-term power loss in PV modules due to leakage current flowing through the module packaging materials. It has been difficult to identify the specific materials and interfaces responsible for degradation based on an analysis of only the total leakage current. A detailed investigation of the leakage current paths within the PV modules, under high voltage bias, is carried out by utilizing a device that measures the independent contributions of various paths in real-time. Knowledge about dominant leakage current paths can be used to quantify the physical and chemical changes …
A Low Voltage Submillisecond-Response Polymer Network Liquid Crystal Spatial Light Modulator, Jie Sun, Shin-Tson Wu, Yasuhiro Haseba
A Low Voltage Submillisecond-Response Polymer Network Liquid Crystal Spatial Light Modulator, Jie Sun, Shin-Tson Wu, Yasuhiro Haseba
Faculty Bibliography 2010s
We report a low voltage and highly transparent polymer network liquid crystal (PNLC) with submillisecond response time. By employing a large dielectric anisotropy LC host JC-BP07N, we have lowered the V-2 pi voltage to 23 V at lambda = 514 nm. This will enable PNLC to be integrated with a high resolution liquid-crystal-on-silicon spatial light modulator, in which the maximum voltage is 24 V. A simple model correlating PNLC performance with its host LC is proposed and validated experimentally. By optimizing the domain size, we can achieve V-2 pi < 15 V with some compromises in scattering and response time.
Response To "Comment On 'Confined Propagation And Near Single-Mode Laser Oscillation In A Gain-Guided, Index Antiguided Optical Fiber'" Appl. Phys. Lett. 102, 026101 (2013), Michael Bass, Martin C. Richardson, John Ballato
Response To "Comment On 'Confined Propagation And Near Single-Mode Laser Oscillation In A Gain-Guided, Index Antiguided Optical Fiber'" Appl. Phys. Lett. 102, 026101 (2013), Michael Bass, Martin C. Richardson, John Ballato
Faculty Bibliography 2010s
No abstract provided.
Insight Into Morphology Changes Of Nanoparticle Laden Droplets In Acoustic Field, Saptarshi Basu, Erick Tijerino, Ranganathan Kumar
Insight Into Morphology Changes Of Nanoparticle Laden Droplets In Acoustic Field, Saptarshi Basu, Erick Tijerino, Ranganathan Kumar
Faculty Bibliography 2010s
Hollow structures with unique morphologies form due to particle agglomeration in acoustically levitated nanofluid functional droplets when subjected to external heating. The final diameter of the structure depends only on the ratio of agglomeration to evaporation time scales for various nanoparticle laden droplets, and not on the type of the suspended particles. These time scales depend only on nanoparticle concentration. This valuable information may be exploited to form microstructures with desired properties from ceramic compounds. Phase diagrams for alumina and silica droplets indicate the transition from a bowl to ring structure depending on concentration.
Electric Field-Induced Monodomain Blue Phase Liquid Crystals, Yuan Chen, Shin-Tson Wu
Electric Field-Induced Monodomain Blue Phase Liquid Crystals, Yuan Chen, Shin-Tson Wu
Faculty Bibliography 2010s
We demonstrate an electric field-induced monodomain blue phase liquid crystal and its application for polarizer-free reflective displays. Superior to multidomain structure, the monodomain exhibits a relatively high reflectance and narrow bandwidth (similar to 25 nm) so the reflected colors look vivid. As the applied voltage increases, the double-twist structure is gradually unwound so that Bragg reflection decreases leading to analogous grayscale. The submillisecond response time enables this reflective display to play videos without image blurs. Such a monodomain blue phase selectively reflects right-handed circularly polarized light when the employed chiral dopant is right-handed, and the reflected light is nearly circularly …
Semiconductor Laser Monolithically Pumped With A Light Emitting Diode Operating In The Thermoelectrophotonic Regime, X. Liu, G. Zhao, Y. Zhang, D. G. Deppe
Semiconductor Laser Monolithically Pumped With A Light Emitting Diode Operating In The Thermoelectrophotonic Regime, X. Liu, G. Zhao, Y. Zhang, D. G. Deppe
Faculty Bibliography 2010s
Data are presented on a monolithic chip that integrates a quantum well semiconductor laser with a high efficiency light emitting diode (LED), with the LED used to optically pump the laser. The LED operates in the thermoelectrophotonic regime that can produce heat absorption, offering the possibility of heat pump action. The internal optical pumping also offers the possibility of very low internal loss in the laser and the prospect of reaching greater than unity power conversion efficiency in the laser chip. The integrated laser chip is operated and tested under continuous-wave room temperature operation.
Laser-Plasma Source Parameters For Kr, Gd, And Tb Ions At 6.6 Nm, Majid Masnavi, John Szilagyi, Homaira Parchamy, Martin C. Richardson
Laser-Plasma Source Parameters For Kr, Gd, And Tb Ions At 6.6 Nm, Majid Masnavi, John Szilagyi, Homaira Parchamy, Martin C. Richardson
Faculty Bibliography 2010s
There is increasing interest in extreme-ultraviolet (EUV) laser-based lamps for sub-10-nm lithography operating in the region of 6.6 nm. A collisional-radiative model is developed as a post-processor of a hydrodynamic code to investigate emission from resonance lines in Kr, Gd, and Tb ions under conditions typical for mass-limited EUV sources. The analysis reveals that maximum conversion efficiencies of Kr occur at 5 x 10(10) W/cm(2), while for Gd and Tb it was similar or equal to 0.9%/2 pi sr for laser intensities of (2-5) x 10(12) W/cm(2).
Recovery Torque Modeling Of Carbon Fiber Reinforced Shape Memory Polymer Nanocomposites, He Shen, Yunjun Xu, Fei Liang, Jihua Gou, Bob Mabbott
Recovery Torque Modeling Of Carbon Fiber Reinforced Shape Memory Polymer Nanocomposites, He Shen, Yunjun Xu, Fei Liang, Jihua Gou, Bob Mabbott
Faculty Bibliography 2010s
Carbon fiber and carbon nanofiber paper (CF&CNFP) can be incorporated into shape memory polymers (SMPs) to increase electrical conductivity and allow high speed electrical actuation with a low power. This paper studies the interactions among the recovery torques of CF&CNFP and SMP and the gravity torque during the shape recovery process. The proposed recovery torque model in a SMP CF&CNFP based structure is validated by experimental data obtained using a recently developed low cost, non-contact measurement testbed.
A Full-Color Reflective Display Using Polymer-Stabilized Blue Phase Liquid Crystal, Jin Yan, Shin-Tson Wu, Kung-Lung Cheng, Jyh-Wen Shiu
A Full-Color Reflective Display Using Polymer-Stabilized Blue Phase Liquid Crystal, Jin Yan, Shin-Tson Wu, Kung-Lung Cheng, Jyh-Wen Shiu
Faculty Bibliography 2010s
We demonstrate a full-color-capability reflective display using red, green, and blue sub-pixels of polymer-stabilized blue phase liquid crystal (BPLC) with different pitch lengths. Vivid colors originate from three-dimensional BPLC photonic crystalline structure. Surface alignment plays a key role to generate uniform and saturated colors in the voltage-off state. Analogous grayscale is achieved by the electric-field-induced unwinding of double-twist structure. This working principle is drastically different from the phase retardation effect of conventional liquid crystal displays. Moreover, the submillisecond response time enables crisp video displays without image blurring. Potential applications for reflective 3D display are also analyzed.
Thermally Induced Secondary Atomization Of Droplet In An Acoustic Field, Saptarshi Basu, Abhishek Saha, Ranganathan Kumar
Thermally Induced Secondary Atomization Of Droplet In An Acoustic Field, Saptarshi Basu, Abhishek Saha, Ranganathan Kumar
Faculty Bibliography 2010s
We study the thermal effects that lead to instability and break up in acoustically levitated vaporizing fuel droplets. For selective liquids, atomization occurs at the droplet equator under external heating. Short wavelength [Kelvin-Helmholtz (KH)] instability for diesel and bio-diesel droplets triggers this secondary atomization. Vapor pressure, latent heat, and specific heat govern the vaporization rate and temperature history, which affect the surface tension gradient and gas phase density, ultimately dictating the onset of KH instability. We develop a criterion based on Weber number to define a condition for the inception of secondary atomization.
Rkky Interaction In Disordered Graphene, Hyunyong Lee, Junghoon Kim, E. R. Mucciolo, Georges Bouzerar, S. Kettemann
Rkky Interaction In Disordered Graphene, Hyunyong Lee, Junghoon Kim, E. R. Mucciolo, Georges Bouzerar, S. Kettemann
Faculty Bibliography 2010s
We investigate the effects of nonmagnetic disorder on the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction in graphene by studying numerically the Anderson model with on-site and hopping disorder on a honeycomb lattice at half filling. We evaluate the strength of the interaction as a function of the distance R between two magnetic ions, as well as their lattice positions and orientations. In the clean limit, we find that the strength of the interaction decays as 1/R-3, with its sign and oscillation amplitude showing strong anisotropy. With increasing on-site disorder, the mean amplitude decreases exponentially at distances exceeding the elastic mean free path. At …
Effects Of Disorder Range And Electronic Energy On The Perfect Transmission In Graphene Nanoribbons, Leandro R. F. Lima, Felipe A. Pinheiro, Rodrigo B. Capaz, Caio H. Lewenkopf, Eduardo R. Mucciolo
Effects Of Disorder Range And Electronic Energy On The Perfect Transmission In Graphene Nanoribbons, Leandro R. F. Lima, Felipe A. Pinheiro, Rodrigo B. Capaz, Caio H. Lewenkopf, Eduardo R. Mucciolo
Faculty Bibliography 2010s
Numerical calculations based on the recursive Green's function method in the tight-binding approximation are performed to calculate the dimensionless conductance g in disordered graphene nanoribbons with Gaussian scatterers. The influence of the transition from short-to long-ranged disorder on g is studied as well as its effects on the formation of a perfectly conducting channel. We also investigate the dependence of electronic energy on the perfectly conducting channel. We propose and calculate a backscattering estimate in order to establish the connection between the perfectly conducting channel (with g = 1) and the amount of intervalley scattering.
Plasma Relaxation And Topological Aspects In Hall Magnetohydrodynamics, Bhimsen K. Shivamoggi
Plasma Relaxation And Topological Aspects In Hall Magnetohydrodynamics, Bhimsen K. Shivamoggi
Faculty Bibliography 2010s
Parker's formulation of isotopological plasma relaxation process in magnetohydrodynamics (MHD) is extended to Hall MHD. The torsion coefficient a in the Hall MHD Beltrami condition turns out now to be proportional to the potential vorticity. The Hall MHD Beltrami condition becomes equivalent to the potential vorticity conservation equation in two-dimensional (2D) hydrodynamics if the Hall MHD Lagrange multiplier beta is taken to be proportional to the potential vorticity as well. The winding pattern of the magnetic field lines in Hall MHD then appears to evolve in the same way as potential vorticity lines in 2D hydrodynamics.
Cascaded Plasmon Resonant Field Enhancement In Nanoparticle Dimers In The Point Dipole Limit, Seyfollah Toroghi, Pieter G. Kik
Cascaded Plasmon Resonant Field Enhancement In Nanoparticle Dimers In The Point Dipole Limit, Seyfollah Toroghi, Pieter G. Kik
Faculty Bibliography 2010s
Cascaded field enhancement in silver dimer nanostructures is investigated using a dipole-dipole interaction model. Field enhancement spectra are evaluated as a function of the particle size difference and inter-particle spacing. We observe three distinct regimes of cascaded field enhancement: hindered cascading, multiplicative cascading, and the ultimate cascading limit, depending on the dimer interaction strength. Multiplicative cascading at small inter-particle spacing leads to analytic expressions for the ultimate internal and external field enhancement factors. For silver dimers in a host with index 1.5, we obtain a maximum internal field enhancement of 2.9 X 10(3), a factor of 75 larger than that …
Low-Bias Negative Differential Resistance In Graphene Nanoribbon Superlattices, Gerson J. Ferreira, Michael N. Leuenberger, Daniel Loss, J. Carlos Egues
Low-Bias Negative Differential Resistance In Graphene Nanoribbon Superlattices, Gerson J. Ferreira, Michael N. Leuenberger, Daniel Loss, J. Carlos Egues
Faculty Bibliography 2010s
We theoretically investigate negative differential resistance (NDR) for ballistic transport in semiconducting armchair graphene nanoribbon (aGNR) superlattices (5 to 20 barriers) at low bias voltages V(SD) < 500 mV. We combine the graphene Dirac Hamiltonian with the Landauer-Buttiker formalism to calculate the current I(SD) through the system. We find three distinct transport regimes in which NDR occurs: (i) a "classical" regime for wide layers, through which the transport across band gaps is strongly suppressed, leading to alternating regions of nearly unity and zero transmission probabilities as a function of V(SD) due to crossing of band gaps from different layers; (ii) a quantum regime dominated by superlattice miniband conduction, with current suppression arising from the misalignment of miniband states with increasing V(SD); and (iii) a Wannier-Stark ladder regime with current peaks occurring at the crossings of Wannier-Stark rungs from distinct ladders. We observe NDR at voltage biases as low as 10 mV with a high current density, making the aGNR superlattices attractive for device applications.
Poly(3-Hexylthiophene) Crystalline Nanoribbon Network For Organic Field Effect Transistors (Vol 96, 243304, 2010), M. Arif, Jianhua Liu, Lei Zhai, Saiful I. Khondaker
Poly(3-Hexylthiophene) Crystalline Nanoribbon Network For Organic Field Effect Transistors (Vol 96, 243304, 2010), M. Arif, Jianhua Liu, Lei Zhai, Saiful I. Khondaker
Faculty Bibliography 2010s
No abstract provided.
Epitaxial Growth Of A Silicene Sheet, Boubekeur Lalmi, Hamid Oughaddou, Hanna Enriquez, Abdelkader Kara, Sébastien Vizzini, Bénidicte Ealet, Bernard Aufray
Epitaxial Growth Of A Silicene Sheet, Boubekeur Lalmi, Hamid Oughaddou, Hanna Enriquez, Abdelkader Kara, Sébastien Vizzini, Bénidicte Ealet, Bernard Aufray
Faculty Bibliography 2010s
Using atomic resolved scanning tunneling microscopy, we present here the experimental evidence of a silicene sheet (graphenelike structure) epitaxially grown on a close-packed silver surface [Ag(111)]. This has been achieved via direct condensation of a silicon atomic flux onto the single-crystal substrate in ultrahigh vacuum conditions. A highly ordered silicon structure, arranged within a honeycomb lattice, is synthesized and present two silicon sublattices occupying positions at different heights (0.02 nm) indicating possible sp(2)-sp(3) hybridizations.
Dynamics Of Entanglement Between A Quantum Dot Spin Qubit And A Photon Qubit Inside A Semiconductor High-Q Nanocavity, Hubert Pascal Seigneur, Gabriel Gonzalez, Michael Niklaus Leuenberger, Winston Vaughan Schoenfeld
Dynamics Of Entanglement Between A Quantum Dot Spin Qubit And A Photon Qubit Inside A Semiconductor High-Q Nanocavity, Hubert Pascal Seigneur, Gabriel Gonzalez, Michael Niklaus Leuenberger, Winston Vaughan Schoenfeld
Faculty Bibliography 2010s
We investigate in this paper the dynamics of entanglement between a QD spin qubit and a single photon qubit inside a quantum network node, as well as its robustness against various decoherence processes. First, the entanglement dynamics is considered without decoherence. In the small detuning regime (Delta = 78 mu eV), there are three different conditions for maximum entanglement, which occur after 71, 93, and 116 picoseconds of interaction time. In the large detuning regime (Delta = 1.5 meV), there is only one peak for maximum entanglement occurring at 625 picoseconds. Second, the entanglement dynamics is considered with decoherence by …