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

1 Nov 2010

Volume 97, Issue 18, Articles (18xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 97, 183105 (2010); http://dx.doi.org/10.1063/1.3506485 (3 pages)

Z. H. Zhang, X. Q. Deng, X. Q. Tan, M. Qiu, and J. B. Pan
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Growth of thick heavily boron-doped diamond single crystals: Effect of microwave power density

R. Issaoui, J. Achard, F. Silva, A. Tallaire, A. Tardieu, A. Gicquel, M. A. Pinault, and F. Jomard

Appl. Phys. Lett. 97, 182101 (2010); http://dx.doi.org/10.1063/1.3511449 (3 pages) | Cited 1 time

Online Publication Date: 1 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The fabrication of diamond-based vertical power devices which are the most suited for high current applications requires the use of thick heavily boron-doped (B-doped) diamond single crystals. Although the growth of thin B-doped diamond films is well controlled over a large concentration range, little is known about the growth conditions leading to heavily doped thick single crystals. In this paper, it was found that the microwave power densities (MWPD) coupled to the plasma used to synthesize B-doped diamond by chemical vapor deposition is one of the key parameters allowing tuning doping efficiencies over two orders of magnitude. At high MWPD (above 100 W cm−3) the boron doping efficiency (DE) is extremely low while further increasing the boron concentration in the gas phase is no use as this leads to plasma instability. On the other hand, when low MWPD are used (<50 W cm−3), DE can be strongly increased but twinning and defects formation hampers the surface morphology. The use of intermediate MWPD densities has been demonstrated as the key in obtaining thick heavily B-doped diamond crystals (>1020 cm−3) with good morphologies.
Show PACS
81.10.-h Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.72.Mm Grain and twin boundaries
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.72.U- Doping and impurity implantation

Ultrafast carrier and phonon dynamics in Bi2Se3 crystals

J. Qi, X. Chen, W. Yu, P. Cadden-Zimansky, D. Smirnov, N. H. Tolk, I. Miotkowski, H. Cao, Y. P. Chen, Y. Wu, S. Qiao, and Z. Jiang

Appl. Phys. Lett. 97, 182102 (2010); http://dx.doi.org/10.1063/1.3513826 (3 pages) | Cited 3 times

Online Publication Date: 1 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ultrafast time-resolved differential reflectivity of Bi2Se3 crystals is studied using optical pump-probe spectroscopy. Three distinct relaxation processes are found to contribute to the initial transient reflectivity changes. The deduced relaxation timescale and the sign of the reflectivity change suggest that electron–phonon interactions and defect-induced charge trapping are the underlying mechanisms for the three processes. After the crystal is exposed to air, the relative strength of these processes is altered and becomes strongly dependent on the excitation photon energy.
Show PACS
63.20.kd Phonon-electron interactions
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.47.jg Time resolved reflection spectroscopy
71.38.-k Polarons and electron-phonon interactions

Tunneling transport properties for metal-oxide-semiconductor diode consisting of ferromagnetic ZnMnO nanocrystals

Sejoon Lee, Youngmin Lee, Yoon Shon, Deuk Young Kim, and Tae Won Kang

Appl. Phys. Lett. 97, 182103 (2010); http://dx.doi.org/10.1063/1.3507894 (3 pages)

Online Publication Date: 2 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Spin-dependent tunneling properties for the metal-semiconductor-oxide diode which was fabricated using ferromagnetic ZnMnO nanocrystals and Ti-Co ferromagnet were investigated. The diode revealed current oscillation packets after tunneling-on, and the peak-to-valley current ratio of the packets showed to be dependent on the temperature-dependent magnetization of the nanocrystals; i.e., the peak-to-valley current ratio of the packets was increased with decreasing the temperature. This result is ascribed to the increased conductance fluctuation due to the increased repulsion probability between spin-polarized and unpolarized carriers because the spin-polarized carriers which are supplied from Ti-Co and are to be injected into n+-Si are transferred through the nanocrystals.
Show PACS
85.30.Kk Junction diodes
85.30.Tv Field effect devices
75.50.Pp Magnetic semiconductors
81.07.Bc Nanocrystalline materials
85.35.-p Nanoelectronic devices
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields

Formation of epitaxial metastable NiGe2 thin film on Ge(100) by pulsed excimer laser anneal

Phyllis S. Y. Lim, Dong Zhi Chi, Poh Chong Lim, Xin Cai Wang, Taw Kuei Chan, Thomas Osipowicz, and Yee-Chia Yeo

Appl. Phys. Lett. 97, 182104 (2010); http://dx.doi.org/10.1063/1.3514242 (3 pages) | Cited 1 time

Online Publication Date: 2 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial nickel digermanide (NiGe2), a metastable phase, was formed by laser annealing Ni on (100) germanium-on-silicon substrates. The NiGe2 formation was investigated using transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, Rutherford backscattering spectroscopy, and first-principles calculations. The formation mechanism of NiGe2 is discussed and is attributed to both the reduced interfacial energy at the NiGe2/Ge(100) interface and the kinetic aspects of the laser annealing reaction associated with phase transformation and film agglomeration.
Show PACS
81.15.Fg Pulsed laser ablation deposition
61.72.Cc Kinetics of defect formation and annealing
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
68.35.Md Surface thermodynamics, surface energies
68.35.Ct Interface structure and roughness
68.35.Rh Phase transitions and critical phenomena

Electric field modulation of thermopower for transparent amorphous oxide thin film transistors

Hirotaka Koide, Yuki Nagao, Kunihito Koumoto, Yuka Takasaki, Tomonari Umemura, Takeharu Kato, Yuichi Ikuhara, and Hiromichi Ohta

Appl. Phys. Lett. 97, 182105 (2010); http://dx.doi.org/10.1063/1.3512870 (3 pages) | Cited 1 time

Online Publication Date: 3 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To clarify the electronic density of states (DOS) around the conduction band bottom for state of the art transparent amorphous oxide semiconductors (TAOSs), InGaZnO4 and In2MgO4, we fabricated TAOS-based transparent thin film transistors (TTFTs) and measured their gate voltage dependence of thermopower (S). TAOS-based TTFTs exhibit an unusual S behavior. The |S|-value abruptly increases but then gradually decreases as Vg increases, clearly suggesting the antiparabolic shaped DOS is hybridized with the original parabolic shaped DOS around the conduction band bottom.
Show PACS
85.30.Tv Field effect devices

High conductivity carbon nanotube wires from radial densification and ionic doping

Jack Alvarenga, Paul R. Jarosz, Chris M. Schauerman, Brian T. Moses, Brian J. Landi, Cory D. Cress, and Ryne P. Raffaelle

Appl. Phys. Lett. 97, 182106 (2010); http://dx.doi.org/10.1063/1.3506703 (3 pages) | Cited 1 time

Online Publication Date: 4 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Application of drawing dies to radially densify sheets of carbon nanotubes (CNTs) into bulk wires has shown the ability to control electrical conductivity and wire density. Simultaneous use of KAuBr4 doping solution, during wire drawing, has led to an electrical conductivity in the CNT wire of 1.3×106 S/m. Temperature-dependent electrical measurements show that conduction is dominated by fluctuation-assisted tunneling, and introduction of KAuBr4 significantly reduces the tunneling barrier between individual nanotubes. Ultimately, the concomitant doping and densification process leads to closer packed CNTs and a reduced charge transfer barrier, resulting in enhanced bulk electrical conductivity.
Show PACS
81.07.De Nanotubes
81.40.Gh Other heat and thermomechanical treatments
81.40.Lm Deformation, plasticity, and creep
73.63.Fg Nanotubes
73.40.Gk Tunneling
61.48.De Structure of carbon nanotubes, boron nanotubes, and other related systems

Spin polarized electric currents in semiconductor heterostructures induced by microwave radiation

C. Drexler, V. V. Bel’kov, B. Ashkinadze, P. Olbrich, C. Zoth, V. Lechner, Ya. V. Terent’ev, D. R. Yakovlev, G. Karczewski, T. Wojtowicz, D. Schuh, W. Wegscheider, and S. D. Ganichev

Appl. Phys. Lett. 97, 182107 (2010); http://dx.doi.org/10.1063/1.3507896 (3 pages) | Cited 1 time

Online Publication Date: 4 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on microwave (mw) radiation induced electric currents in (Cd,Mn)Te/(Cd,Mg)Te and InAs/(In,Ga)As quantum wells subjected to an external in-plane magnetic field. The current generation is attributed to the spin-dependent energy relaxation of electrons heated by mw radiation. The relaxation produces equal and oppositely directed electron flows in the spin-up and spin-down subbands yielding a pure spin current. The Zeeman splitting of the subbands in the magnetic field leads to the conversion of the spin flow into a spin-polarized electric current.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.25.-b Spin polarized transport
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect

Magnetocurrent of ballistically injected electrons in insulating silicon

Hyuk-Jae Jang and Ian Appelbaum

Appl. Phys. Lett. 97, 182108 (2010); http://dx.doi.org/10.1063/1.3511681 (3 pages) | Cited 1 time

Online Publication Date: 5 November 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
By using ballistic hot-electron injection to achieve lateral conduction through an otherwise fully insulating undoped silicon channel, we are able to study magnetic field suppression of charge transport in a regime normally excluded in Ohmic magnetoresistance measurements. Exceptionally large magnetocurrent changes of >16 000% at 45 K in magnetic fields of ≈ 2 T are observed, with differential reduction of over 6.2 T−1. Temperature-, electrostatic back-gate-, and magnetic field angle-dependence are presented. This phenomenon is attributed to strong space-charge effects in the dilute three-dimensional electron gas created by nonequilibrium injection.
Show PACS
72.20.My Galvanomagnetic and other magnetotransport effects
72.20.Ht High-field and nonlinear effects
72.25.Hg Electrical injection of spin polarized carriers
77.22.Jp Dielectric breakdown and space-charge effects
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close