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

16 Oct 2006

Volume 89, Issue 16, Articles (16xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 89, 164101 (2006); http://dx.doi.org/10.1063/1.2362602 (3 pages)

Yen-Wen Lu and Chang-Jin(CJ) Kim
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Growth of long wavelength InxGa1−xAsySb1−y layers on GaAs from liquid phase

A. Kumar and P. S. Dutta

Appl. Phys. Lett. 89, 162101 (2006); http://dx.doi.org/10.1063/1.2360899 (3 pages) | Cited 2 times

Online Publication Date: 16 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Lattice mismatched layers of InxGa1−xAsySb1−y with band edge corresponding to a wavelength of 10.9 μm have been grown on GaAs substrates using a self-graded compositionally organized near-equilibrium growth process based on quaternary melt thermochemistry. A variable composition quaternary acts as a buffer layer between the GaAs substrate and the final layer of uniform composition. Layers of a constant composition with thicknesses as high as 100 μm have been achieved. The dislocation densities in the layers are as low as 8×105 cm−2 even for a lattice mismatch of 13.08%. van der Pauw measurements showed room temperature electron mobility as high as 1.4×104 cm2/V s and carrier concentration of 4.2×1016 cm−3. With further optimization in the growth conditions and improvements in the material quality, the grown layers are expected to be suitable for infrared optoelectronics, high speed electronic devices, and magnetoresistive sensors.
Show PACS
68.55.A- Nucleation and growth
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
73.61.Ey III-V semiconductors
72.20.Fr Low-field transport and mobility; piezoresistance
82.60.-s Chemical thermodynamics
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

High resolution photoemission spectroscopy: Evidence for strong chemical interaction between Mg and 3,4,9,10-perylene-tetracarboxylic dianhydride

G. Gavrila, D. R. T. Zahn, and W. Braun

Appl. Phys. Lett. 89, 162102 (2006); http://dx.doi.org/10.1063/1.2356305 (3 pages) | Cited 4 times

Online Publication Date: 16 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The interface formation between Mg and 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) was investigated by high resolution soft x-ray photoemission spectroscopy. The interface chemistry was obtained after fitting the core level spectra as a function of Mg thickness. At the initial stage of deposition, a strong chemical interaction between Mg and the single bonded oxygen atoms of PTCDA is observed leading to the formation of MgO and a modified organic molecule. Based on the experimental evidence, the molecular structure of the modified molecule is proposed. Moreover, the changes observed in the measured C1s core level spectra are supported by density functional theory calculations.
Show PACS
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
79.60.Jv Interfaces; heterostructures; nanostructures
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
73.20.-r Electron states at surfaces and interfaces
71.15.Mb Density functional theory, local density approximation, gradient and other corrections

Magnetotransport properties of Ge channels with extremely high compressive strain

K. Sawano, Y. Kunishi, Y. Shiraki, K. Toyama, T. Okamoto, N. Usami, and K. Nakagawa

Appl. Phys. Lett. 89, 162103 (2006); http://dx.doi.org/10.1063/1.2354467 (3 pages) | Cited 3 times

Online Publication Date: 17 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ge channel structures with extremely high compressive strain up to 2.8% were fabricated and their magnetotransport properties were evaluated. It was found that at the same hole density the sample with the higher strain showed the lower hole effective mass and that the compressive strain effectively reduced the effective mass. The Dingle ratios obtained were very high (>5) for all samples, indicating that remote impurity scattering was a dominant scattering mechanism rather than high angle scatterings caused by degradation of the channel layers. This result strongly suggests that Ge channels with extremely high strain are very promising for high performance complementary-metal-oxide-semiconductor applications.
Show PACS
81.05.Cy Elemental semiconductors
72.20.My Galvanomagnetic and other magnetotransport effects
72.80.Cw Elemental semiconductors
72.10.Fk Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect)
62.20.F- Deformation and plasticity
81.40.Lm Deformation, plasticity, and creep

Electron transport in semiconducting chiral carbon nanotubes

M. Z. Kauser and P. P. Ruden

Appl. Phys. Lett. 89, 162104 (2006); http://dx.doi.org/10.1063/1.2362973 (3 pages) | Cited 4 times

Online Publication Date: 17 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report on electron transport characteristics for semiconducting, single wall, chiral carbon nanotubes. The Boltzmann transport equation is solved indirectly by the ensemble Monte Carlo method. The basis for the transport calculations is provided by electronic structure calculations in the framework of a simple tight binding model. Scattering mechanisms considered are due to the electron-phonon interactions involving longitudinal acoustic, longitudinal optic, and radial breathing mode phonons. Due to the smaller Brillouin zone, Umklapp scattering processes occur with much greater frequency in chiral carbon nanotubes than in achiral nanotubes. The transient and steady-state transport characteristics are found to be dependent on the chirality for semiconducting carbon nanotubes with similar diameters.
Show PACS
73.63.Fg Nanotubes
61.46.Fg Nanotubes
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials
73.22.-f Electronic structure of nanoscale materials and related systems
71.15.Ap Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)
71.38.-k Polarons and electron-phonon interactions

Improved memory window for Ge nanocrystals embedded in SiON layer

Chun-Hao Tu, Ting-Chang Chang, Po-Tsun Liu, Hsin-Chou Liu, Simon M. Sze, and Chun-Yen Chang

Appl. Phys. Lett. 89, 162105 (2006); http://dx.doi.org/10.1063/1.2362972 (3 pages) | Cited 17 times

Online Publication Date: 18 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The formation of germanium (Ge) nanocrystals embedded in silicon oxygen nitride (SiON) is proposed for charge storage elements in this work. The Ge nanocrystals can be nucleated after the oxidation process of silicon germanium nitride (SiGeN) layer at high temperatures. Compared to the control samples of Ge nanocrystals/SiO2/Si structure and SiON/Si stack memory, the proposed Ge nanocrystals/SiON/Si memory obtained superior memory window, even larger than the typical sum of both. It is considered that the extra interface trap states between Ge and SiON film were generated as Ge nanocrystals were embedded in SiON layer.
Show PACS
73.40.Ty Semiconductor-insulator-semiconductor structures
81.65.Mq Oxidation
73.20.At Surface states, band structure, electron density of states

Bias dependent inversion of tunneling magnetoresistance in Fe/GaAs/Fe tunnel junctions

J. Moser, M. Zenger, C. Gerl, D. Schuh, R. Meier, P. Chen, G. Bayreuther, W. Wegscheider, D. Weiss, C.-H. Lai, R.-T. Huang, M. Kosuth, and H. Ebert

Appl. Phys. Lett. 89, 162106 (2006); http://dx.doi.org/10.1063/1.2364163 (3 pages) | Cited 21 times

Online Publication Date: 18 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors investigated spin dependent transport through Fe/GaAs/Fe tunnel junctions. The tunneling magnetoresistance (TMR) effect was probed for different types of Fe/GaAs interfaces. For interfaces cleaned by hydrogen plasma the TMR effect is increased and is observable at room temperature. If an epitaxial Fe/GaAs(001) interface is involved, the tunnel junction exhibits a bias dependent inversion of the TMR effect. This is a first experimental signature for band structure effects at an Fe/GaAs interface and is relevant for spin injection experiments.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.47.-m Magnetotransport phenomena; materials for magnetotransport
72.25.Mk Spin transport through interfaces
75.50.Bb Fe and its alloys

Electrode-molecular semiconductor contacts: Work-function-dependent hole injection barriers versus Fermi-level pinning

N. Koch and A. Vollmer

Appl. Phys. Lett. 89, 162107 (2006); http://dx.doi.org/10.1063/1.2364166 (3 pages) | Cited 36 times

Online Publication Date: 18 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Contacts between two molecular organic semiconductors [p-sexiphenyl (6P) and pentacene] and conducting polymers (CPs) were investigated with photoemission spectroscopy. The dependence of the hole injection barrier (HIB) at 6P/CP interfaces on substrate work function (ϕ) exhibited a transition from almost Schottky-Mott limit-like behavior to Fermi-level pinning. For pentacene, no significant variation of the HIB as function of ϕ was observed, despite the large range of ϕ spanned by the CPs (4.4–5.9 eV). The results on contacts with CPs are compared to those with metals, where none of the two limiting cases for HIBs as a function of ϕ was observed.
Show PACS
73.40.Cg Contact resistance, contact potential
72.80.Le Polymers; organic compounds (including organic semiconductors)
73.30.+y Surface double layers, Schottky barriers, and work functions
79.60.Bm Clean metal, semiconductor, and insulator surfaces
79.60.Fr Polymers; organic compounds

Charge-injection-induced dynamic screening and origin of hysteresis in field-modulated transport in single-wall carbon nanotubes

Aravind Vijayaraghavan, Swastik Kar, Caterina Soldano, Saikat Talapatra, Omkaram Nalamasu, and Pulickel M. Ajayan

Appl. Phys. Lett. 89, 162108 (2006); http://dx.doi.org/10.1063/1.2362586 (3 pages) | Cited 25 times

Online Publication Date: 19 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Gate modulated transport in semiconducting single-wall carbon nanotubes shows significant hysteresis in their transfer characteristics. The origin of this hysteresis is generally attributed to the screening of the gate voltage due to the movement of mobile charges/ions in the inherent presence of a trapping/detrapping mechanism in the adjacent dielectric, as in conventional silicon metal-oxide-semiconductor field-effect transistors. However, recent works have conjectured that the screening charges may originate from the nanotube itself. From an extensive study of the temperature dependence of the hysteresis behavior in nanotube field-effect transistors the authors experimentally establish this alternative mechanism, in which the screening charges are injected from the nanotube itself into the surrounding dielectric. Any detailed trapping/detrapping mechanism does not appear to play a significant role, and all experimental results can be simply explained in terms of a capacitive charging of the surrounding dielectric due to the charge injection.
Show PACS
85.35.Kt Nanotube devices
85.30.Tv Field effect devices

Intrinsic ferromagnetic properties of Ti0.94Fe0.06O2/Ti0.94Mn0.06O2 superlattice films for dilute magnetic semiconductor applications

Nak-Jin Seong, Soon-Gil Yoon, Young-Hun Jo, Myung-Hwa Jung, Chae-Ryong Cho, Jun-Mo Yang, Dong-Jun Park, Jae-Wook Lee, and Jeong-Yong Lee

Appl. Phys. Lett. 89, 162109 (2006); http://dx.doi.org/10.1063/1.2360234 (3 pages) | Cited 7 times

Online Publication Date: 19 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Superlattice films have been proposed to get dilute magnetic semiconductor (DMS) with an intrinsic room-temperature ferromagnetism. For a TiO2-based DMS superlattice structure, each layer was alternately doped by two different transition metals (Fe and Mn) and deposited to a thickness of approximately 2.7 Å on r-Al2O3(1102) substrates by pulsed laser deposition. Samples of Ti0.94Fe0.06O2 (TiFeO), Ti0.94Mn0.06O2 (TiMnO), and Ti0.94(Fe0.03Mn0.03)O2 show a low remanent magnetization and coercive field, as well as superparamagnetic features at room temperature. On the other hand, superlattice films (TiFeO/TiMnO) show a high remanent magnetization and coercive field, resulting in intrinsic ferromagnetic properties. The superlattice films composed of alternating layers of Ti0.94Fe0.06O2 and Ti0.94Mn0.06O2 exhibit intrinsic ferromagnetic properties for dilute magnetic semiconductor applications.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Pp Magnetic semiconductors
81.15.Fg Pulsed laser ablation deposition
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Effect of dislocation scattering on the transport properties of InN grown on GaN substrates by molecular beam epitaxy

Kejia (Albert) Wang, Yu Cao, John Simon, Jing Zhang, Alexander Mintairov, James Merz, Douglas Hall, Thomas Kosel, and Debdeep Jena

Appl. Phys. Lett. 89, 162110 (2006); http://dx.doi.org/10.1063/1.2364456 (3 pages) | Cited 19 times

Online Publication Date: 20 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report the structural, optical, and transport properties of high quality InN epitaxial films grown on GaN substrates by plasma-assisted molecular beam epitaxy. They have found a strong correlation between the structural quality and the measured carrier mobilities. Comparison of temperature-dependent Hall data with a theoretical transport model indicates that the electron mobility in state-of-art InN is limited by charged dislocation scattering. The model predicts that an order-of-magnitude increase in electron mobilities can be achieved by the reduction of dislocation densities in InN.
Show PACS
73.61.Ey III-V semiconductors
68.55.-a Thin film structure and morphology
68.55.A- Nucleation and growth
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
72.10.Fk Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect)
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

Validity/invalidity of Schottky-Mott rules for Schottky contacts to III-V nitride semiconductor heterostructures

Changzhi Lu and S. Noor Mohammad

Appl. Phys. Lett. 89, 162111 (2006); http://dx.doi.org/10.1063/1.2358956 (3 pages) | Cited 5 times

Online Publication Date: 20 October 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Carrier transport through the metal/semiconductor and metal/semiconductor/semiconductor (M/S/S) Schottky contact interfaces has been studied. Metal/n-GaN, metal/n-AlxGa1−xN, and metal/n-AlxGa1−xN/n-GaN diodes have been chosen for the study. It has been observed that, owing to the presence of the piezoelectric polarization field and a quantum well at the AlxGa1−xN/GaN interface, the AlxGa1−xN/GaN contacts exhibit properties distinctly different from those of the AlxGa1−xN contacts. The superiority of the AlxGa1−xN/GaN contacts to that of the AlxGa1−xN contacts largely disappears at high temperatures. While the GaN and AlxGa1−xN contacts appear to obey the Schottky-Mott rule, the AlxGa1−xN/GaN contacts tend to disobey it.
Show PACS
85.30.Kk Junction diodes
85.30.Hi Surface barrier, boundary, and point contact devices
73.30.+y Surface double layers, Schottky barriers, and work functions
73.40.Ns Metal-nonmetal contacts
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.63.Hs Quantum wells
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close