APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

3 Apr 2006

Volume 88, Issue 14, Articles (14xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 88, 143508 (2006); http://dx.doi.org/10.1063/1.2191448 (3 pages)

R. Chan, M. Feng, N. Holonyak, A. James, and G. Walter
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Negative differential thermal resistance and thermal transistor

Baowen Li, Lei Wang, and Giulio Casati

Appl. Phys. Lett. 88, 143501 (2006); http://dx.doi.org/10.1063/1.2191730 (3 pages) | Cited 107 times

Online Publication Date: 3 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the first model of a thermal transistor to control heat flow. Like its electronic counterpart, our thermal transistor is a three-terminal device with the important feature that the current through the two terminals can be controlled by small changes in the temperature or in the current through the third terminal. This control feature allows us to switch the device between “off” (insulating) and “on” (conducting) states or to amplify a small current. The thermal transistor model is possible because of the negative differential thermal resistance.
Show PACS
07.20.-n Thermal instruments and apparatus

Copper drift in high-dielectric-constant tantalum oxide thin films under bias temperature stress

Pushkar Jain, Jasbir S. Juneja, A. Mallikarjunan, E. J. Rymaszewski, and T.-M. Lu

Appl. Phys. Lett. 88, 143502 (2006); http://dx.doi.org/10.1063/1.2191832 (3 pages) | Cited 1 time

Online Publication Date: 3 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The use of high-dielectric-constant (high-κ) materials for embedded capacitors is becoming increasingly important. Tantalum oxide (Ta2O5) is a prominent candidate as a high-κ material for embedded capacitor use. Metal drift in Ta2O5 (κ ∼ 25) was investigated by bias temperature stress and triangular voltage sweep testing techniques on metal/Ta2O5/SiO2/Si structures. At a temperature of 300 °C and 0.75 MV/cm bias conditions, Al, Ta, and Ti do not diffuse in Ta2O5, but Cu clearly showed a drift. The Cu drift is attributed to the lack of a stable Cu oxide which can limit Cu ion generation and penetration.
Show PACS
84.32.Tt Capacitors
85.30.Tv Field effect devices

Electric field tuning characteristics of a ferrite-piezoelectric microwave resonator

Y. K. Fetisov and G. Srinivasan

Appl. Phys. Lett. 88, 143503 (2006); http://dx.doi.org/10.1063/1.2191950 (3 pages) | Cited 57 times

Online Publication Date: 3 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The fabrication and characterization of an electric field-tunable yttrium iron garnet (YIG)-lead zirconate titanate (PZT) microwave resonator are discussed. The device is based on ferromagnetic resonance for YIG. The tunability is accomplished through magnetoelectric interactions. For an electric field E = 10 kV/cm across PZT, a frequency shift of 18–25 MHz that was an order of magnitude higher the frequency width of the absorption profile for the resonator was measured. Upon reversal of the direction of E, the shift also reversed. The YIG-PZT bilayer structures could form the basis for rapid, electric field tunable, passive microwave resonators and filters.
Show PACS
84.40.-x Radiowave and microwave (including millimeter wave) technology
85.70.Ge Ferrite and garnet devices
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance

Two-dimensional array of coupled nanomechanical resonators

Maxim K. Zalalutdinov, Jeffrey W. Baldwin, Martin H. Marcus, Robert B. Reichenbach, Jeevak M. Parpia, and Brian H. Houston

Appl. Phys. Lett. 88, 143504 (2006); http://dx.doi.org/10.1063/1.2190448 (3 pages) | Cited 16 times

Online Publication Date: 3 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Two-dimensional arrays of coupled nanomechanical plate-type resonators were fabricated in single crystal silicon using e-beam lithography. Collective modes were studied using a double laser setup with independent positioning of the point laser drive and interferometric motion detector. The formation of a wide acoustic band has been demonstrated. Localization due to disorder (mistune) was identified as a parameter that limits the propagation of the elastic waves. We show that all 400 resonators in our 20×20 array participate in the extended modes and estimate group velocity and density of states. Applications utilizing the resonator arrays for radio frequency signal processing are discussed.
Show PACS
07.10.Cm Micromechanical devices and systems
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
85.40.Hp Lithography, masks and pattern transfer

Voltage gain dependence of the negative differential conductance width in silicon single-hole transistors

Kousuke Miyaji, Masumi Saitoh, and Toshiro Hiramoto

Appl. Phys. Lett. 88, 143505 (2006); http://dx.doi.org/10.1063/1.2192637 (3 pages) | Cited 12 times

Online Publication Date: 3 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The full width at half maximum (FWHM) of the negative differential conductance (NDC) characteristics in room temperature (RT)-operating silicon single-hole transistors (SHTs) has been studied by experiments and calculations. It is found that when the voltage gain of the SHT is higher, sharper NDC and smaller FWHM are achieved. Lower drain coupling is considered to be the main reason for the small FWHM in a resonant tunneling system of RT-operating SHTs. FWHM of NDC of as small as 95 mV has been obtained in a SHT with the gain of as high as 5.2 at RT, which is the highest value of the gain ever reported. The device is in the form of an ultranarrow wire channel metal oxide semiconductor field-effect transistor, which shows large Coulomb blockade oscillations at RT and has extremely small drain capacitance due to its ultranarrow channel structure. NDC can now be designed by device parameters, showing further potential for application to low-voltage, low-power NDC circuits.
Show PACS
85.30.Tv Field effect devices
85.35.Ds Quantum interference devices
85.35.Gv Single electron devices

Surface NH3 anneal on strained Si0.5Ge0.5 for metal-oxide-semiconductor applications with HfO2 as gate dielectric

Jidong Huang, Nan Wu, Qingchun Zhang, Chunxiang Zhu, M. F. Li, Andrew A. O. Tay, Zhi-Yuan Cheng, Chris W. Leitz, and Anthony Lochtefeld

Appl. Phys. Lett. 88, 143506 (2006); http://dx.doi.org/10.1063/1.2191468 (3 pages) | Cited 6 times

Online Publication Date: 4 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this Letter, metal-oxide-semiconductor capacitors were fabricated and characterized on compressively strained Si50Ge50 on Si0.8Ge0.2 virtual substrates by using metal-organic chemical vapor deposition HfO2 as gate dielectric and TaN as metal gate electrode. It is demonstrated that surface nitridation treatment using NH3 annealing prior to HfO2 deposition effectively prevents the growth of GeOx at the interfacial layer which exists on SiGe surface with direct deposition of HfO2. X-ray photoelectron spectroscopic analysis suggests that the nitridation process tends to occur to Si atoms rather than to Ge atoms and results in the formation of an interfacial layer of SiNxOy on the SiGe surface. Capacitors with the surface nitridation treatment show good capacitance-voltage characteristics with negligible hysteresis, much smaller interface trap charge density, and significantly improved gate leakage current in comparison with those of capacitors made without nitridation treatment. The surface nitridation seems to be a promising method for the formation of high quality high-κ gate stack on strained SiGe substrate.
Show PACS
84.32.Tt Capacitors
85.30.Tv Field effect devices

Multi-island single-electron devices from self-assembled colloidal nanocrystal chains

Dirk N. Weiss, Xavier Brokmann, Laurie E. Calvet, Marc A. Kastner, and Moungi G. Bawendi

Appl. Phys. Lett. 88, 143507 (2006); http://dx.doi.org/10.1063/1.2189012 (3 pages) | Cited 15 times

Online Publication Date: 5 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the fabrication of multi-island single-electron devices made by lithographic contacting of self-assembled alkanethiol-coated gold nanocrystals. The advantages of this method, which bridges the dimensional gap between lithographic and NC sizes, are (1) the fact that all tunnel junctions are defined by self-assembly rather than lithography and (2) the high ratio of gate capacitance to total capacitance. The rich electronic behavior of a double-island device, measured at 4.2 K, is predicted by combining finite element and Monte Carlo simulations, and it can be fully explained by the standard theory of Coulomb blockade with very few adjustable parameters.
Show PACS
85.35.Gv Single electron devices
85.35.Ds Quantum interference devices
81.16.Dn Self-assembly
81.16.Nd Micro- and nanolithography

Collector current map of gain and stimulated recombination on the base quantum well transitions of a transistor laser

R. Chan, M. Feng, N. Holonyak, A. James, and G. Walter

Appl. Phys. Lett. 88, 143508 (2006); http://dx.doi.org/10.1063/1.2191448 (3 pages) | Cited 17 times

Online Publication Date: 5 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Data are presented showing significant structure in the collector I-V characteristics of a transistor laser, a decrease (“compression”) in the common-emitter gain (β ≡ ΔIC/ΔIB), that can be mapped in some detail and related to quantum well (QW) carrier recombination. The change in gain (β) and laser wavelength corresponding to stimulated recombination (stimulated emission) on QW transitions, which is compared with operation in spontaneous recombination (cavity Q spoiled), is used with conventional transistor charge analysis to reveal the dynamic properties of the transistor laser.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
85.60.Dw Photodiodes; phototransistors; photoresistors

Strained Pt Schottky diodes on n-type Si and Ge

M. H. Liao, P.-S. Kuo, S.-R. Jan, S. T. Chang, and C. W. Liu

Appl. Phys. Lett. 88, 143509 (2006); http://dx.doi.org/10.1063/1.2191831 (3 pages) | Cited 13 times

Online Publication Date: 5 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The variation of electron barrier height and built-in voltage of Pt Schottky diodes on the mechanically strained n-type Si and Ge is investigated experimentally and theoretically. The mechanical strain is measured by Raman spectroscopy and analyzed by the finite element method. The built-in voltage and barrier height measured by capacitance-voltage and current-voltage methods, respectively, decrease with increasing external tensile strain. The reduction of the built-in voltage and barrier height originates mainly from the conduction band lowering with strain. The extracted value of conduction band lowering is consistent with the theoretical calculations using the “stress-free” boundary condition.
Show PACS
85.30.Kk Junction diodes
85.30.Hi Surface barrier, boundary, and point contact devices

Formation of the physical vapor deposited CdS/Cu(In,Ga)Se2 interface in highly efficient thin film solar cells

M. Rusu, Th. Glatzel, A. Neisser, C. A. Kaufmann, S. Sadewasser, and M. Ch. Lux-Steiner

Appl. Phys. Lett. 88, 143510 (2006); http://dx.doi.org/10.1063/1.2190768 (3 pages) | Cited 11 times

Online Publication Date: 5 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the buffer/absorber interface formation in highly efficient (14.5%, air mass 1.5) ZnO/CdS/Cu(In,Ga)Se2 solar cells with a physical vapor deposited CdS buffer. For Se-decapped Cu(In,Ga)Se2 (CIGSe) absorbers we observe sulfur passivation of the CIGSe grain boundaries during CdS growth and at the interface a thermally stimulated formation of a region with a higher band gap than that of the absorber bulk, determining the height of the potential barrier at the CdS/CIGSe interface. For air-exposed CIGSe samples the grain boundary passivation is impeded by a native oxide/adsorbate layer at the CIGSe surface determining the thermal stability of the potential barrier height.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.05.Dz II-VI semiconductors
84.60.Jt Photoelectric conversion
81.65.Rv Passivation
61.72.Mm Grain and twin boundaries
71.20.Nr Semiconductor compounds

Room temperature ultraviolet emission at 357 nm from polysilane based organic light emitting diode

Asha Sharma, Monica Katiyar, Deepak, Shu Seki, and Seiichi Tagawa

Appl. Phys. Lett. 88, 143511 (2006); http://dx.doi.org/10.1063/1.2193652 (3 pages) | Cited 13 times

Online Publication Date: 6 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have fabricated an organic light emitting diode using poly(n-butylphenylsilane) which has an emission in deep ultraviolet at 357 nm at room temperature. The device structure used is glass/indium tin oxide/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)/polysilane (emitting material)/calcium/aluminum. These devices emit ultraviolet light with a turn-on voltage of 8 V. The electroluminescence spectrum of the device in the ultraviolet range is identical to the photoluminescence spectrum of the polysilane thin film. From these devices, we also observe an additional emission in the visible region, which is not present in the photoluminescence spectrum of the material. The visible emission has a color coordinate of (0.36,0.35), which can be modulated to a required white light coordinate by down converting the ultraviolet emission.
Show PACS
85.60.Jb Light-emitting devices

Electro-optic switch in ferroelectric thin films mediated by surface plasmons

S. W. Liu and Min Xiao

Appl. Phys. Lett. 88, 143512 (2006); http://dx.doi.org/10.1063/1.2193968 (3 pages) | Cited 15 times

Online Publication Date: 6 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose an optical switch in simple waveguide geometry with a metal thin film sandwiched between two layers of electro-optic materials. Its mechanism is based on the distinct responsive behaviors of two surface plasmon modes in the metal film to the cladding films. By exploiting the specific distribution of surface plasmon fields in metals, an effective optical switch with a very low crosstalk −27 dB and a switching bias of 59 kV/cm is achieved for Ba0.5Sr0.5TiO3 ferroelectric films. The dependences of the optical switch’s crosstalk and switching bias on the geometric parameters of the structure are also analyzed.
Show PACS
78.20.Jq Electro-optical effects
77.80.Fm Switching phenomena
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
42.65.Pc Optical bistability, multistability, and switching, including local field effects
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Viscous damping of microresonators for gas composition analysis

Yang Xu, J.-T. Lin, Bruce W. Alphenaar, and Robert S. Keynton

Appl. Phys. Lett. 88, 143513 (2006); http://dx.doi.org/10.1063/1.2193347 (3 pages) | Cited 10 times

Online Publication Date: 7 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The damping effect of various gas environments on a silicon, lateral microresonator implemented with piezoresistive detection is investigated in this study. The resonant frequency of the cantilever shifts due to viscous damping by an amount that is directly determined by the molar mass of the gas, thereby providing a method to determine the composition of the gas environment. In addition, the microresonator demonstrates the ability to perform CO2 composition analysis using this nonreaction based detection method. The advantages of this gas analysis method are that it is simple, repeatable, reversible and not limited to reactive gases.
Show PACS
07.10.Cm Micromechanical devices and systems
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
51.20.+d Viscosity, diffusion, and thermal conductivity

Dynamic range of ultrabroadband terahertz detection using GaAs photoconductors

A. Hussain and S. R. Andrews

Appl. Phys. Lett. 88, 143514 (2006); http://dx.doi.org/10.1063/1.2193427 (3 pages) | Cited 6 times

Online Publication Date: 7 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electromagnetic transients with frequency components spanning the far and midinfrared are coherently detected by means of the polarization current induced in an electron-hole plasma optically excited in As implanted GaAs. The impulse response is governed by the frequency dependence of the photocarrier mobility and density and the lattice contribution to the dielectric constant. Compared with electro-optic sampling using thin ZnTe crystals, photoconductive detection can yield a comparable or greater dynamic range up to 40 THz.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors

Effect of Te precipitates on the performance of CdZnTe detectors

G. A. Carini, A. E. Bolotnikov, G. S. Camarda, G. W. Wright, R. B. James, and L. Li

Appl. Phys. Lett. 88, 143515 (2006); http://dx.doi.org/10.1063/1.2189912 (3 pages) | Cited 47 times

Online Publication Date: 7 April 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Measurements using the National Synchrotron Light Source provided a detailed comparisons of the microscale detector response and infrared microscopy images for CdZnTe Frisch-ring x-ray and gamma detectors. Analysis of the data showed conclusively that local deteriorations of the electron charge collection and x-ray device response fully correlate with the presence of Te precipitates as seen in the IR images. Effects of the surface processing conditions on the detector performance were also clearly observed.
Show PACS
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors
29.40.Wk Solid-state detectors
81.65.-b Surface treatments
64.75.-g Phase equilibria
81.30.Mh Solid-phase precipitation
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close