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

25 Aug 2003

Volume 83, Issue 8, pp. 1497-1679

Issue Cover Spotlight Figure

Appl. Phys. Lett. 83, 1671 (2003); http://dx.doi.org/10.1063/1.1604161 (3 pages)

Wenyi Cai, Christopher F. Powell, Yong Yue, Suresh Narayanan, Jin Wang, Mark W. Tate, Matthew J. Renzi, Alper Ercan, Ernest Fontes, and Sol M. Gruner
Enlarge Image | Read More
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Distribution of built-in electrical potential in GaInP2/GaAs tandem-junction solar cells

C.-S. Jiang, D. J. Friedman, J. F. Geisz, H. R. Moutinho, M. J. Romero, and M. M. Al-Jassim

Appl. Phys. Lett. 83, 1572 (2003); http://dx.doi.org/10.1063/1.1602575 (3 pages) | Cited 8 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Distributions of built-in potential in GaInP2/GaAs tandem-junction solar cells were investigated by scanning Kelvin probe microscopy. Two states of potential distribution resulting from flattening of band bending and charge accumulation on either the top or bottom p–n junction were observed under short circuit, depending on the illumination spectra. With an external bias voltage, the voltage change always happened on the junction with the charge accumulation, and the potential distribution between the two states became less sensitive to illumination spectra. © 2003 American Institute of Physics.
Show PACS
84.60.Jt Photoelectric conversion
73.61.Ey III-V semiconductors

Electrical characteristics of Au and Ag Schottky contacts on n-ZnO

A. Y. Polyakov, N. B. Smirnov, E. A. Kozhukhova, V. I. Vdovin, K. Ip, Y. W. Heo, D. P. Norton, and S. J. Pearton

Appl. Phys. Lett. 83, 1575 (2003); http://dx.doi.org/10.1063/1.1604173 (3 pages) | Cited 82 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Au and Ag Schottky contacts on the epiready (0001)Zn surface of bulk n-ZnO crystals show Schottky barrier heights of 0.65–0.70 eV from capacitance–voltage measurements, activation energies for reverse saturation currents of 0.3–0.4 eV and saturation current densities ranging from 10−5 A cm−2 on surfaces etched in HCl to 8×10−7 A cm−2 on solvent cleaned samples. The diode ideality factors were in the range 1.6–1.8 under all conditions. The properties of both the Au and the Ag Schottky diodes were degraded by heating in vacuum to temperatures even as low as 365 K. The degradation mechanisms during annealing were different in each case, with the Au showing reaction with the ZnO surface and the Ag contacts showing localized delamination. Mechanical polishing of the ZnO surface prior to contact deposition produced a high-resistivity damaged layer with prominent deep level defects present with activation energies of 0.55 and 0.65 eV. © 2003 American Institute of Physics.
Show PACS
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
68.35.Ct Interface structure and roughness
73.20.At Surface states, band structure, electron density of states
73.61.Ga II-VI semiconductors
73.20.Hb Impurity and defect levels; energy states of adsorbed species

Current rectification in a single GaN nanowire with a well-defined p–n junction

Guosheng Cheng, Andrei Kolmakov, Youxiang Zhang, Martin Moskovits, Ryan Munden, Mark A. Reed, Guangming Wang, Daniel Moses, and Jinping Zhang

Appl. Phys. Lett. 83, 1578 (2003); http://dx.doi.org/10.1063/1.1604190 (3 pages) | Cited 34 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF


See Also: Publisher's Note

Show Abstract
This letter discusses Mg incorporation in GaN nanowires with diameters ∼35 nm, fabricated by vapor–liquid–solid synthesis in p-type nanowires. Turning on the Mg doping halfway through the synthesis produced nanowires with p–n junctions that showed excellent rectification properties down to 2.6 K. The nanowires are shown to possess good-quality, crystalline, hexagonal GaN inner cores surrounded by an amorphous GaN outer layer. Most wires grow such that the crystalline c axis is normal to the long axis of the nanowire. The temperature dependence of the current–voltage characteristics is consistent with electron tunneling through a voltage-dependent barrier. © 2003 American Institute of Physics.
Show PACS
73.40.Ei Rectification
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
61.72.uj III-V and II-VI semiconductors
85.40.Ry Impurity doping, diffusion and ion implantation technology
73.61.Ey III-V semiconductors
81.05.Ea III-V semiconductors
73.63.Nm Quantum wires
61.46.-w Structure of nanoscale materials
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Doping-induced type-II to type-I transition and interband optical gain in InAs/AlSb quantum wells

K. I. Kolokolov and C. Z. Ning

Appl. Phys. Lett. 83, 1581 (2003); http://dx.doi.org/10.1063/1.1605236 (3 pages) | Cited 1 time

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show that proper doping of the barrier regions can convert the well-known type-II InAs/AlSb quantum wells (QWs) to type I, producing strong interband transitions comparable to regular type-I QWs. The interband gain for TM mode is as high as 4000 1/cm, thus providing an important alternative material system in the midinfrared wavelength range. We also study the TE and TM gain as functions of doping level and intrinsic electron–hole density. © 2003 American Institute of Physics.
Show PACS
78.67.De Quantum wells
73.21.Fg Quantum wells
81.07.St Quantum wells
61.72.uj III-V and II-VI semiconductors
78.55.Cr III-V semiconductors
81.05.Ea III-V semiconductors
85.40.Ry Impurity doping, diffusion and ion implantation technology
back to top
RSS Feeds

Magnetovibrational coupling in small cantilevers

Alexey A. Kovalev, Gerrit E. W. Bauer, and Arne Brataas

Appl. Phys. Lett. 83, 1584 (2003); http://dx.doi.org/10.1063/1.1603338 (3 pages) | Cited 9 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A nanomagnetomechanical system consisting of a cantilever and a thin magnetic film is predicted to display magnetovibrational modes, which should enable applications for sensors and actuators. The “polaritonic” modes can be detected by line splittings in ferromagnetic resonance spectra. © 2003 American Institute of Physics.
Show PACS
75.80.+q Magnetomechanical effects, magnetostriction
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
75.70.-i Magnetic properties of thin films, surfaces, and interfaces
07.10.Cm Micromechanical devices and systems
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance

Mössbauer effect probe of local Jahn–Teller distortion in Fe-doped colossal magnetoresistive manganites

Zhao-hua Cheng, Zhi-hong Wang, Nai-li Di, Zhi-qi Kou, Guang-jun Wang, Rui-wei Li, Yi Lu, Qing-an Li, Bao-gen Shen, and R. A. Dunlap

Appl. Phys. Lett. 83, 1587 (2003); http://dx.doi.org/10.1063/1.1605232 (3 pages) | Cited 5 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The local structure of the Fe-doped La1−xCaxMnO3 (x = 0.00–1.00) compounds has been investigated by means of Mössbauer spectroscopy. 57Fe Mössbauer spectra provide direct evidence of Jahn–Teller distortion in these manganites. On the basis of the Mössbauer results, the Jahn–Teller coupling was estimated. It is noteworthy that the Ca-concentration dependence of the Jahn–Teller coupling strength is very consistent with the magnetic phase diagram. Our results reveal that Mössbauer spectroscopy cannot only detect the local structural distortion, but also provide a technique to investigate the Jahn–Teller coupling of Fe-doped La1−xCaxMnO3 colossal magnetoresistive perovskites. © 2003 American Institute of Physics.
Show PACS
76.80.+y Mössbauer effect; other γ-ray spectroscopy
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
61.66.Fn Inorganic compounds
75.47.Gk Colossal magnetoresistance
75.47.Lx Magnetic oxides

Room temperature formation of half-metallic Fe3O4 thin films for the application of spintronic devices

Jin Pyo Hong, Sung Bok Lee, Young Woo Jung, Jong Hyun Lee, Kap Soo Yoon, Ki Woong Kim, Chae Ok Kim, Chang Hyo Lee, and Myoung Hwa Jung

Appl. Phys. Lett. 83, 1590 (2003); http://dx.doi.org/10.1063/1.1604466 (3 pages) | Cited 30 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Half-metallic Fe3O4 films were prepared at room temperature using a rf sputtering system specially integrated with an external rf source. Primary emphasis was placed on obtaining a large amount of active oxygen radicals through an external electrode for efficient deposition. The insertion of an external electrode was found to be critical for room temperature growth of Fe3O4 thin films. The structural and electrical properties gave shift and broadening effects to the Verwey temperature at various powers. The magnetization could only be saturated when a 300 Oe field was applied along an easy axis of magnetization during growth. However, there was no sign of saturation up to 5 T under zero-field growth. © 2003 American Institute of Physics.
Show PACS
72.25.-b Spin polarized transport
75.70.Ak Magnetic properties of monolayers and thin films
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
81.15.Cd Deposition by sputtering
68.55.-a Thin film structure and morphology
71.30.+h Metal-insulator transitions and other electronic transitions
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Nucleation of superconductivity in an Al mesoscopic disk with magnetic dot

D. S. Golubović, W. V. Pogosov, M. Morelle, and V. V. Moshchalkov

Appl. Phys. Lett. 83, 1593 (2003); http://dx.doi.org/10.1063/1.1604939 (3 pages) | Cited 20 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the nucleation of superconductivity in a mesoscopic Al disk with a Co/Pd magnetic dot placed on the top by measuring the normal/superconducting phase boundary Tc(B). The measurements have revealed a pronounced asymmetry in the phase boundary with respect to the direction of the applied magnetic field, indicating an enhancement of the critical field when an applied magnetic field is oriented parallel to the magnetization of the magnetic dot. The theoretical Tc(B) curve is in a good agreement with the experimental data. © 2003 American Institute of Physics.
Show PACS
75.75.-c Magnetic properties of nanostructures
74.78.Na Mesoscopic and nanoscale systems
74.25.Ha Magnetic properties including vortex structures and related phenomena
74.25.Op Mixed states, critical fields, and surface sheaths
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)
75.50.Cc Other ferromagnetic metals and alloys
75.50.Tt Fine-particle systems; nanocrystalline materials

Angular dependence of spin-transfer switching in a magnetic nanostructure

F. B. Mancoff, R. W. Dave, N. D. Rizzo, T. C. Eschrich, B. N. Engel, and S. Tehrani

Appl. Phys. Lett. 83, 1596 (2003); http://dx.doi.org/10.1063/1.1604936 (3 pages) | Cited 59 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We measured switching of a thin film nanomagnet driven by spin-polarized current in giant magnetoresistance spin valves as small as 50 nm×100 nm. Spin-transfer reversal is observed in both dc current and magnetic field sweeps, with a switching current of ∼5 mA, for example, for a bit with ∼900 Oe switching field in zero current. We studied the dependence of spin-transfer switching on the relative angle ϕ between the layer magnetizations by using a magnetic field to orient the magnetization of a bulk magnetic layer at an angle to a patterned layer held in place by shape anisotropy. The critical current is a minimum for collinear magnetizations and diverges as 1/∣cos ϕ∣ as ϕ increases to 90°, consistent with switching current calculations using the Slonczewski spin-transfer torque model. © 2003 American Institute of Physics.
Show PACS
75.47.De Giant magnetoresistance
85.75.Mm Spin polarized resonant tunnel junctions
75.50.Tt Fine-particle systems; nanocrystalline materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
back to top
RSS Feeds

Spectroscopic ellipsometry study of epitaxially grown Pb(Mg1/3Nb2/3)O3–PbTiO3/MgO/TiN/Si heterostructures

W. S. Tsang, K. Y. Chan, C. L. Mak, and K. H. Wong

Appl. Phys. Lett. 83, 1599 (2003); http://dx.doi.org/10.1063/1.1603339 (3 pages) | Cited 14 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (PMN–PT) thin films have been grown on MgO/TiN-buffered Si(001) substrates using pulsed laser deposition. Their structural properties and surface morphology were examined by x-ray diffraction and scanning electron microscopy, respectively. All PMN–PT films grown at 670 °C show a cube-on-cube epitaxial relationship of PMN–PT(100)∥MgO(100)∥TiN(100)∥Si(100). Discernable interfaces between layers in the heterostructures and crack-free surfaces are evident. A spectroscopic ellipsometer was used to study the optical characteristics of the films. It was revealed that the refractive index of the PMN–PT is ∼2.50 as measured at 635 nm. This value is only slightly less than that of the PMN–PT single crystal of 2.60. Our results suggest that the PMN–PT/MgO/TiN/Si heterostructure has an excellent potential for use in integrated optical waveguide devices. © 2003 American Institute of Physics.
Show PACS
78.66.Nk Insulators
68.35.Ct Interface structure and roughness
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
68.55.-a Thin film structure and morphology
81.15.Fg Pulsed laser ablation deposition
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Significant changes in the ferroelectric properties of BiFeO3 modified SrBi2Ta2O9

A. Srinivas, Dong-Wan Kim, and Kug Sun Hong

Appl. Phys. Lett. 83, 1602 (2003); http://dx.doi.org/10.1063/1.1604483 (3 pages) | Cited 6 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The solid solution of BiFeO3 (BF)–SrBi2Ta2O9 (SBT) prepared at a concentration of 1:1 ratio, shows significant changes in the structure and dielectric properties. The obtained compound although similar to a three-layered Aurivillius phase, is noticeably a Bi and oxygen deficient SBT phase. Due to this, the unit cell shows a subtle decrease in its volume and the dielectric properties show a decline. The layered perovskite structure sustains the strain associated with the loss of Bi and oxygen. SrBi3Ta2FeO12 has been synthesized by solid-state route and the single phase was confirmed by x-ray diffraction. The Curie temperature shows a marginal increase (an increase of 20 °C) compared to that of SBT. Polarization versus electric measurements show a slim hysteresis loop with a Pmax of 4.3 μC/cm2. The electromechanical coupling coefficient KP values are evaluated from the resonance and antiresonance measurements. © 2003 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.Dj Domain structure; hysteresis
77.80.B- Phase transitions and Curie point
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.22.Ej Polarization and depolarization
77.22.Gm Dielectric loss and relaxation
61.66.Fn Inorganic compounds
61.50.Lt Crystal binding; cohesive energy
77.22.Ch Permittivity (dielectric function)
77.65.-j Piezoelectricity and electromechanical effects

Broadband dielectric spectroscopy of (1−x)BiScO3–xPbTiO3 piezoelectrics

V. Porokhonskyy, S. Kamba, A. Pashkin, M. Savinov, J. Petzelt, R. E. Eitel, and C. A. Randall

Appl. Phys. Lett. 83, 1605 (2003); http://dx.doi.org/10.1063/1.1604945 (3 pages) | Cited 14 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Dielectric spectra of high-temperature piezoelectric (1−x)BiScO3–xPbTiO3 of composition near the morphotropic phase boundary (x ≅ 0.64) were investigated in the frequency range of 100 Hz–1 THz at temperatures between 10 and 900 K. Below the ferroelectric phase transition Tc ≅ 700 K, in addition to polar phonons, two other polarization mechanisms were detected: one, centered in the 100 MHz–1 GHz range probably caused by sound generation due to ferroelectric-ferroelastic domain wall motion; another evidences dynamic disorder of some ions. The former process, characterized by the temperature-independent mean relaxation time, vanishes below ∼ 250 K. The latter mechanism, caused by compositional disorder, results in the nearly frequency-independent losses (1/f noise) at low temperatures. © 2003 American Institute of Physics.
Show PACS
77.65.-j Piezoelectricity and electromechanical effects
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.22.Gm Dielectric loss and relaxation
77.80.B- Phase transitions and Curie point
77.80.Dj Domain structure; hysteresis
62.20.D- Elasticity

Effect of external mechanical constraints on the phase diagram of epitaxial PbZr1−xTixO3 thin films—thermodynamic calculations and phase-field simulations

Y. L. Li, S. Choudhury, Z. K. Liu, and L. Q. Chen

Appl. Phys. Lett. 83, 1608 (2003); http://dx.doi.org/10.1063/1.1600824 (3 pages) | Cited 34 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The phase diagram of a PbZr1−xTixO3 (PZT) film constrained by a much thicker substrate was studied using both thermodynamic calculations and phase-field approach. It was found that the ferroelectric transition temperature is increased with substrate constraint regardless of the nature of the constraint, i.e., tensile or compressive. The maximum increase in the transition temperature occurs near x = 0.5, and the morphotropic phase boundary is shifted considerably by the substrate constraint. It is shown that the orthorhombic phase (∣P1∣ = ∣P2∣ ≠ 0, P3 = 0) that does not exist in the bulk becomes stable under a tensile constraint, and the rhombohedral phase (∣P1∣ = ∣P2∣ = ∣P3∣ ≠ 0) in the bulk is distorted in the constrained film, i.e., ∣P1∣ = ∣P2∣ ≠ 0, ∣P3∣ ≠ 0. The phase diagrams obtained by the phase-field approach indicated that the stability region for the tetragonal phase is much wider than that obtained from the thermodynamic calculations assuming a single-domain, especially under tensile substrate constraint. The discrepancy between the two methods becomes larger as substrate constraint changes from compressive to tensile, implying that thermodynamic calculations are unreliable for constructing stability diagram of PZT, particularly under a tensile constraint. © 2003 American Institute of Physics.
Show PACS
68.55.Nq Composition and phase identification
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.B- Phase transitions and Curie point

Temperature- and field-dependent leakage current of Pt/(Ba0.7Sr0.3)TiO3 interface

Hao Yang, Bin Chen, Kun Tao, Xianggang Qiu, Bo Xu, and Bairu Zhao

Appl. Phys. Lett. 83, 1611 (2003); http://dx.doi.org/10.1063/1.1604181 (3 pages) | Cited 12 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Pt/(Ba0.7Sr0.3)TiO3(BST)/YBa2Cu3O7−x(YBCO) capacitors on SrTiO3 substrates were fabricated. The temperature and field dependence of the leakage current of Pt/BST interface were studied in the temperature range from 100 K to 320 K and in an electric field up to 3 MV/cm. For a middle electric field (<1 MV/cm), the leakage current shows space-charge-limited-current behavior in the temperature range from 100 K to 200 K. In the case of a high electric field (>1.8 MV/cm), the leakage mechanism is governed by the Fowler–Nordheim tunneling in the whole measured temperature range. © 2003 American Institute of Physics.
Show PACS
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
84.32.Tt Capacitors
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.-e Ferroelectricity and antiferroelectricity
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
73.50.Fq High-field and nonlinear effects
73.40.Gk Tunneling

Dielectric and piezoelectric properties of relaxor Pb(Sc1/2Nb1/2)O3 thin films

B. J. Kuh, W. K. Choo, K. Brinkman, D. Damjanovic, and N. Setter

Appl. Phys. Lett. 83, 1614 (2003); http://dx.doi.org/10.1063/1.1604189 (3 pages) | Cited 6 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Pure perovskite Pb(Sc1/2Nb1/2)O3 thin films without pyrochlore phase were prepared by the sol–gel method on TiO2/Pt/TiO2/SiO2/Si substrates. Films exhibited (111) preferred orientation and columnar microstructure. Diffuse phase transitions with permittivity maximum decreasing in value and shifting toward higher temperature with increasing frequency and slim polarization-electric field hysteresis loops typical for relaxors were observed. The maximum field-induced piezoelectric d33 coefficient measured with ac electric field of 14 kV/cm was 58 pm/V. The d33–dc electric field relation is virtually hysteresis free. © 2003 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.65.Bn Piezoelectric and electrostrictive constants
68.55.-a Thin film structure and morphology
77.22.Gm Dielectric loss and relaxation
77.22.Ch Permittivity (dielectric function)
77.80.B- Phase transitions and Curie point
77.80.Dj Domain structure; hysteresis
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
back to top
RSS Feeds

Tunneling microscopy and spectroscopy of multiwalled boron nitride nanotubes

R. Czerw, S. Webster, D. L. Carroll, S. M. C. Vieira, P. R. Birkett, C. A. Rego, and S. Roth

Appl. Phys. Lett. 83, 1617 (2003); http://dx.doi.org/10.1063/1.1601308 (3 pages) | Cited 18 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Atomic resolution images of multiwalled boron nitride nanotubes have been obtained using scanning tunneling microscopy operating at tunneling currents below 20 pA and biases of approximately −2.5 V. Lattice images acquired with negative sample biases exhibit trigonal symmetry that is interpreted as resulting from nitrogen states. Tunneling spectroscopy confirms band gaps between 4.5 eV and 4.8 eV for tube diameters above 5 nm. Tunneling barrier height measurements made using standard current–distance analysis yields Φ∼6.3±0.7 eV for the boron nitride nanotubes. © 2003 American Institute of Physics.
Show PACS
61.46.-w Structure of nanoscale materials
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)

Synthesis and characterization of superconducting single-crystal Sn nanowires

Mingliang Tian, Jinguo Wang, Joseph Snyder, James Kurtz, Ying Liu, Peter Schiffer, Thomas E. Mallouk, and M. H. W. Chan

Appl. Phys. Lett. 83, 1620 (2003); http://dx.doi.org/10.1063/1.1601692 (3 pages) | Cited 51 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Single-crystal superconducting tin nanowires with diameters of 40–160 nm have been prepared by electrochemical deposition in porous polycarbonate membranes. Structural characterization through transmission electron microscopy and x-ray diffraction showed that the nanowires are highly oriented along the [100] direction. Although the superconducting transition temperature is close to the bulk value of 3.7 K, the effect of reduced dimensionality is clearly evident in the electrical transport properties of the thinnest wires (40 nm diameter). Magnetization measurements show that the critical field of the nanowires increases significantly with decreasing diameter to ∼ 0.3 T for the thinnest wires, nearly an order of magnitude larger than the bulk value. © 2003 American Institute of Physics.
Show PACS
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)
81.07.Bc Nanocrystalline materials
74.10.+v Occurrence, potential candidates
74.25.Ha Magnetic properties including vortex structures and related phenomena
61.46.-w Structure of nanoscale materials
74.25.Op Mixed states, critical fields, and surface sheaths

Universal description of channel conductivity for nanotube and nanowire transistors

S. V. Rotkin, H. E. Ruda, and A. Shik

Appl. Phys. Lett. 83, 1623 (2003); http://dx.doi.org/10.1063/1.1604462 (3 pages) | Cited 14 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A theory of drift-diffusion transport in a low-dimensional field-effect transistor is developed. Two cases of a semiconductor nanowire and a single-wall nanotube are considered using self-consistent electrostatics to obtain a general expression for the transconductance. This quantum-wire channel device description is shown to differ from a classical device theory because of the specific nanowire charge density distribution. © 2003 American Institute of Physics.
Show PACS
85.35.Kt Nanotube devices
85.30.Tv Field effect devices
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.63.Nm Quantum wires
73.63.Fg Nanotubes
73.50.Dn Low-field transport and mobility; piezoresistance

Field electron emission from nanostructured heterogeneous HfNxOy films

M. Y. Liao, Y. Gotoh, H. Tsuji, and J. Ishikawa

Appl. Phys. Lett. 83, 1626 (2003); http://dx.doi.org/10.1063/1.1604944 (3 pages) | Cited 2 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanostructured heterogeneous HfNxOy films comprising of nanoscale conductive hafnium nitride grains embedded in a matrix of dielectric oxide or oxynitride were deposited on silicon substrate by magnetron sputtering at room temperature. Electron emission with low threshold field 25 V/μm and good current stability were reported. The field emission characteristics depend on the concentration of hafnium nitride phase, revealing the nature of heterogeneous structure. Field enhancement in HfNxOy film was explained in terms of the interaction between the conductive grains separated by dielectric layers under external electric field. The experiment is expected to open a group of nanostructured heterogeneous material consisting of stable conductive nitride and insulating oxide for field emitter, and also provide an insight into the emission mechanism of carbon films. © 2003 American Institute of Physics.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption

Three-dimensional nanolithography using proton beam writing

J. A. van Kan, A. A. Bettiol, and F. Watt

Appl. Phys. Lett. 83, 1629 (2003); http://dx.doi.org/10.1063/1.1604468 (3 pages) | Cited 54 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the utilization of a focused mega-electron-volt (MeV) proton beam to write accurate high-aspect-ratio structures at sub-100 nm dimensions. Typically, a MeV proton beam is focused to a sub-100 nm spot size and scanned over a suitable resist material. When the proton beam interacts with matter it follows an almost straight path. The secondary electrons induced by the primary proton beam have low energy and therefore limited range, resulting in minimal proximity effects. These features enable smooth three-dimensional structures to be direct written into resist materials. Initial tests have shown this technique capable of writing high aspect ratio walls of 30 nm width with sub-3 nm edge smoothness. © 2003 American Institute of Physics.
Show PACS
81.16.Nd Micro- and nanolithography
85.40.Hp Lithography, masks and pattern transfer
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Fabrication of 60-nm transistors on 4-in. wafer using nanoimprint at all lithography levels

Wei Zhang and Stephen Y. Chou

Appl. Phys. Lett. 83, 1632 (2003); http://dx.doi.org/10.1063/1.1600505 (3 pages) | Cited 43 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanoimprint lithography (NIL) is a paradigm-shift method that has shown sub-10-nm resolution, high throughput, and low cost. To make NIL a next-generation lithography tool to replace conventional lithography, one must demonstrate the needed overlay accuracy in multilayer NIL, large-area uniformity, and low defect density. Here, we present the fabrication of 60-nm channel metal–oxide–semiconductor field-effect transistors on whole 4-in. wafers using NIL at all lithography levels. The nanotransistors exhibit excellent operational characteristics across the wafer. The statistics from consecutive multiwafer processing show an average overlay accuracy of 500 nm over the entire 4-in. wafer. The accuracy is much better when the field size is reduced. The overlay accuracies are limited by the current alignment method and can be improved substantially. The work presents a significant advance in nanoimprint development and its applications in manufacturing of integrated electrical, optical, chemical, and biological nanocircuits. © 2003 American Institute of Physics.
Show PACS
85.40.Hp Lithography, masks and pattern transfer
81.16.Nd Micro- and nanolithography
85.30.Tv Field effect devices

Optical properties of ZnO rods formed by metalorganic chemical vapor deposition

B. P. Zhang, N. T. Binh, Y. Segawa, K. Wakatsuki, and N. Usami

Appl. Phys. Lett. 83, 1635 (2003); http://dx.doi.org/10.1063/1.1605803 (3 pages) | Cited 160 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-quality ZnO rods were formed directly on sapphire (0001) substrates by metalorganic chemical vapor deposition. The rods exhibited free exciton and very sharp bound exciton emissions at low temperatures. By increasing the excitation intensity, biexciton emission was observed. Temperature dependence of the emission spectra suggested that the emission peak at ∼ 3.315 eV, which had been attributed to neutral acceptor-bound exciton emission, is due to donor-acceptor pairs. The acceptor binding energy was determined to be about 107 meV, which agrees well with that estimated from a hydrogen-atom-like acceptor model. © 2003 American Institute of Physics.
Show PACS
78.55.Et II-VI semiconductors
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
78.67.-n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures

Imaging helical potassium hexaniobate nanotubes

G. H. Du, L.-M. Peng, Q. Chen, S. Zhang, and W. Z. Zhou

Appl. Phys. Lett. 83, 1638 (2003); http://dx.doi.org/10.1063/1.1605235 (3 pages) | Cited 15 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Potassium hexaniobate nanotubes have been synthesized at room temperature and characterized by high-resolution transmission electron microscopy (HRTEM) and energy-dispersive x-ray analysis. It is shown that HRTEM images may be used effectively to determine the helicity of the nanotubes, and, in particular, it is found that almost all nanotubes have their axes pointing within a few degrees from the [100] direction of the K4Nb6O17 structure. © 2003 American Institute of Physics.
Show PACS
61.46.-w Structure of nanoscale materials
81.07.De Nanotubes
68.37.Lp Transmission electron microscopy (TEM)
back to top
RSS Feeds

High-frequency, high-sensitivity acoustic sensor implemented on ALN/Si substrate

C. Caliendo and P. Imperatori

Appl. Phys. Lett. 83, 1641 (2003); http://dx.doi.org/10.1063/1.1604482 (3 pages) | Cited 9 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
AlN films, 1.6–6.3 μm thick, were sputtered at 200 °C on Si(100) and Si(111) substrates. The films were crack-free, uniform, and c-axis oriented. The experimental phase velocities of surface acoustic waves (SAW) propagating in the AlN/Si structures were estimated and showed only a small discrepancy (20–40 m/s) compared to the calculated theoretical values. A SAW resonator (SAWR)-based chemical sensor, operating at about 700 MHz, was implemented on AlN/Si. The SAWR surface was covered with a polymer film sensitive to relative humidity (RH) changes, already tested for RH sensing in previous works on SAW delay lines implemented on AlN/Si and ZnO/Si and operating at about 130 MHz. The RH mass sensitivity and the detection limit of the SAWR sensor improved by 38% and by one order of magnitude, respectively, compared to the delay line-based sensors previously tested. © 2003 American Institute of Physics.
Show PACS
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
07.07.Vx Hygrometers; hygrometry
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
68.35.Iv Acoustical properties
73.61.Ey III-V semiconductors
81.15.Cd Deposition by sputtering
43.58.Wc Electrical and mechanical oscillators

H2O effect on the stability of organic thin-film field-effect transistors

Yong Qiu, Yuanchuan Hu, Guifang Dong, Liduo Wang, Junfeng Xie, and Yaning Ma

Appl. Phys. Lett. 83, 1644 (2003); http://dx.doi.org/10.1063/1.1604193 (3 pages) | Cited 120 times

Online Publication Date: 19 August 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Degradation of organic thin-film field-effect transistors (OTFTs) with pentacene as the active material has been studied. It was found that the field-effect mobility of the device decreased by 30% and the on/off current ratio decreased to one fifth after the OTFTs had been stored in atmosphere for 500 h. Through surface morphology analysis by atomic force microscopy and absorption analysis by infrared spectroscopy, it was found that the adsorption of H2O on the pentacene layer was the main reason for the degradation. Remarkable improvement in the device performance was achieved by device encapsulation with UV curable resin. © 2003 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
73.61.Ph Polymers; organic compounds
68.35.B- Structure of clean surfaces (and surface reconstruction)
78.66.Qn Polymers; organic compounds
78.30.Jw Organic compounds, polymers
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close