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

24 Jan 2011

Volume 98, Issue 4, Articles (04xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 98, 043101 (2011); http://dx.doi.org/10.1063/1.3536475 (3 pages)

Zhichao Ruan and Shanhui Fan
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Radial elasticity of single-walled carbon nanotube measured by atomic force microscopy

Y. H. Yang and W. Z. Li

Appl. Phys. Lett. 98, 041901 (2011); http://dx.doi.org/10.1063/1.3546170 (3 pages) | Cited 6 times

Online Publication Date: 24 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Effective radial modulus (Eradial) of straight single-walled carbon nanotubes (SWCNTs) grown directly on quartz substrate have been measured by using well-calibrated tapping mode and contact mode atomic force microscopies. It is found that the measured Eradial decreases from 57 to 9 GPa as the diameter of the SWCNTs increases from 0.92 to 1.91 nm. The current experimental results are consistent with the recently reported simulation data in both the data pattern and values. The method used in this research can also be applied to measure the mechanical properties of other low-dimension nanostructures, such as nanowires and nanodots.
Show PACS
81.07.De Nanotubes
81.16.-c Methods of micro- and nanofabrication and processing
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.dj Poisson's ratio

Influence of ultrathin amorphous silicon layers on the nucleation of microcrystalline silicon films under hydrogen plasma treatment

Z. W. Zuo, W. T. Guan, Y. Wang, J. Lu, J. Z. Wang, L. Pu, Y. Shi, Y. D. Zheng, X. Y. Luo, and H. H. Wang

Appl. Phys. Lett. 98, 041902 (2011); http://dx.doi.org/10.1063/1.3548674 (3 pages) | Cited 1 time

Online Publication Date: 24 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Microstructures of phosphorus-doped hydrogenated microcrystalline silicon (μc-Si:H) thin films deposited by plasma-enhanced chemical vapor deposition are certainly dependent on the thickness of the H2 plasma-treated amorphous silicon (a-Si:H) layers. An ultrathin H-treated a-Si:H layer is beneficial in obtaining a very thin μc-Si:H film with high conductivity. Experimental results indicate that H2 plasma treatment induces the occurrence of high-pressure H2 in microvoids and causes compressive stress inside the ultrathin a-Si:H layers, thereby enhancing the generation of strained Si–Si bonds and nucleation sites and consequently accelerating the nucleation of μc-Si:H films.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.ag Semiconductors
61.72.Qq Microscopic defects (voids, inclusions, etc.)

Misfit relaxation of La0.7Sr0.3MnO3 thin films by a nanodot segregation mechanism

P. Abellán, C. Moreno, F. Sandiumenge, X. Obradors, and M.-J. Casanove

Appl. Phys. Lett. 98, 041903 (2011); http://dx.doi.org/10.1063/1.3549182 (3 pages) | Cited 3 times

Online Publication Date: 25 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Partially segregated La0.7Sr0.3MnO3 (LSMO) nanocomposite films are shown to exhibit a thickness dependent self-assembled structure. The morphological evolution of the nanocomposite and the misfit strain of the LSMO phase are linked through the topological distribution of La–Sr oxide nanodots within the film. Misfit relaxation occurs above a critical thickness, hc, coinciding with the nucleation of La–Sr oxide nanodots at the film-substrate interface. Below hc, the same dots outcrop the film surface, forming islands. As a consequence of this misfit relaxation mechanism, an enhancement in the magnetoresistance with increasing thickness is measured.
Show PACS
81.16.Dn Self-assembly
75.47.Pq Other materials
68.35.Dv Composition, segregation; defects and impurities
68.37.Og High-resolution transmission electron microscopy (HRTEM)

Defect dynamics and spectral observation of twinning in single crystalline LaAlO3 under subbandgap excitation

J. Q. Chen, X. Wang, Y. H. Lu, A. Roy Barman, G. J. You, G. C. Xing, T. C. Sum, S. Dhar, Y. P. Feng, Ariando, Q.-H. Xu, and T. Venkatesan

Appl. Phys. Lett. 98, 041904 (2011); http://dx.doi.org/10.1063/1.3543840 (3 pages) | Cited 2 times

Online Publication Date: 25 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the photoluminescence and ultrafast dynamics of LaAlO3 crystal. The photoluminescence consists of a broad spectrum and two sharp peaks, which arise from various defect levels within the bandgap. A doublet splitting of roughly 6 nm is seen in these two sharp peaks. An Al displacement of 0.09 Å in a sublattice, which is possible because of twinning, is adequate to explain the spectral splitting. Femtosecond pump probe experiments reveal further that many of these defect levels have a few picosecond decay times while the lowest defect states have decay times longer than nanosecond to the valence band.
Show PACS
78.55.Hx Other solid inorganic materials
71.20.Ps Other inorganic compounds
71.55.Ht Other nonmetals
61.72.Mm Grain and twin boundaries
78.47.J- Ultrafast spectroscopy (<1 psec)
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Second harmonic generation probing of dopant type and density at the Si/SiO2 interface

Julie L. Fiore, Vasiliy V. Fomenko, Dora Bodlaki, and Eric Borguet

Appl. Phys. Lett. 98, 041905 (2011); http://dx.doi.org/10.1063/1.3505356 (3 pages) | Cited 3 times

Online Publication Date: 25 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time-dependent second-harmonic generation (TD-SHG) is shown to be a sensitive, noncontact probe of dopant type and concentration at Si/SiO2 interfaces. TD-SHG signal magnitude increases for n-Si(111)/SiO2, while for p-Si(111)/SiO2 TD-SHG is nonmonotonic. This behavior is interpreted as a consequence of SHG sensitivity to electric fields induced by interfacial charge transfer and trapping.
Show PACS
78.20.Jq Electro-optical effects
61.72.up Other materials

Hole-channel conductivity in epitaxial graphene determined by terahertz optical-Hall effect and midinfrared ellipsometry

T. Hofmann, A. Boosalis, P. Kühne, C. M. Herzinger, J. A. Woollam, D. K. Gaskill, J. L. Tedesco, and M. Schubert

Appl. Phys. Lett. 98, 041906 (2011); http://dx.doi.org/10.1063/1.3548543 (3 pages) | Cited 12 times

Online Publication Date: 25 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report noncontact, optical determination of free-charge carrier mobility, sheet density, and resistivity parameters in epitaxial graphene at room temperature using terahertz and midinfrared ellipsometry and optical-Hall effect measurements. The graphene layers are grown on Si- and C-terminated semi-insulating 6H silicon carbide polar surfaces. Data analysis using classical Drude functions and multilayer modeling render the existence of a p-type channel with different sheet densities and effective mass parameters for the two polar surfaces. The optically obtained parameters are in excellent agreement with results from electrical Hall effect measurements.
Show PACS
72.80.Vp Electronic transport in graphene
73.61.Wp Fullerenes and related materials
72.20.My Galvanomagnetic and other magnetotransport effects

Continuously voltage-tunable electroluminescence from a monolayer of ZnS quantum dots

Rong-Wei Xuan (宣荣卫), Jian-Ping Xu (徐建萍), Xiao-Song Zhang (张晓松), Ping Li (李萍), Cheng-Yuan Luo (罗程远), Yan-Yu Wu (吴燕宇), and Lan Li (李岚)

Appl. Phys. Lett. 98, 041907 (2011); http://dx.doi.org/10.1063/1.3544570 (3 pages) | Cited 4 times

Online Publication Date: 26 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A monolayer electroluminescence (EL) device with ZnS quantum dots (QDs) as emitting layer was fabricated by spin-coating technique. Continuously tunable EL spectra from ZnS QDs are observed at room temperature. By increasing excitation voltage, the EL spectra can be tuned from yellow green (560 nm) to blue (470 nm), corresponding to chromaticity coordinates from (0.45, 0.52) to (0.22, 0.26). In order to understand the mechanism of the device, the dependences of the photoluminescence of the ZnS QDs on temperature, excitation energy, and particle size have been studied, respectively, which indicates that the possible mechanisms of tunable EL spectra are related to selective excitation of QDs with different particle sizes.
Show PACS
78.60.Fi Electroluminescence
78.55.Et II-VI semiconductors
78.67.Hc Quantum dots
64.75.Jk Phase separation and segregation in nanoscale systems
81.05.Dz II-VI semiconductors

Realization of freestanding wrinkled thin films with flexible deformability

Tomohiro Maruyama, Hiroyuki Hirakata, Akio Yonezu, and Kohji Minoshima

Appl. Phys. Lett. 98, 041908 (2011); http://dx.doi.org/10.1063/1.3549203 (3 pages) | Cited 1 time

Online Publication Date: 26 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a technique for producing freestanding films having a wrinkled structure. In an experiment, we discovered that a wrinkle pattern can be made on the surface of a sacrificial resin layer by applying compressive strain under the appropriate conditions. Using this phenomenon, we made a freestanding wrinkled film by depositing a film on the wrinkled resin surface and then removing the resin layer with an organic solvent. Uniaxial tensile tests for 300 nm thick freestanding copper wrinkled films revealed that the films have superior deformability: the fracture elongation is more than ten times larger than that of its straight film counterpart.
Show PACS
81.40.Lm Deformation, plasticity, and creep
62.20.mm Fracture
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
68.60.Bs Mechanical and acoustical properties
81.70.Bt Mechanical testing, impact tests, static and dynamic loads
62.20.F- Deformation and plasticity

Strain dependence of thermal conductivity of [0001]-oriented GaN nanowires

Kwangsub Jung, Maenghyo Cho, and Min Zhou

Appl. Phys. Lett. 98, 041909 (2011); http://dx.doi.org/10.1063/1.3549691 (3 pages) | Cited 4 times

Online Publication Date: 28 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermomechanical behavior of [0001]-oriented GaN nanowires with 2.26 and 3.55 nm in diameter under tensile loading is analyzed using molecular dynamics simulations with the Green–Kubo method and quantum correction. A phase transformation from wurtzite to a tetragonal structure is observed. The thermal conductivity is found to decrease as the wires undergo tensile deformation and phase transformation, except for the smallest diameter and temperatures above 1495 K at which it remains largely constant as the axial strain increases. The different trends appear to result from phonon behavior changes primarily associated with the surface structures of the nanowires at the different conditions.
Show PACS
66.70.Df Metals, alloys, and semiconductors
81.40.Lm Deformation, plasticity, and creep
64.70.Nd Structural transitions in nanoscale materials
64.70.kg Semiconductors
68.65.La Quantum wires (patterned in quantum wells)
63.22.Gh Nanotubes and nanowires

Thickness dependence of the integrated Bragg intensity for statistically disturbed silicon crystals

J. Will, A. Gröschel, M. Weißer, and A. Magerl

Appl. Phys. Lett. 98, 041910 (2011); http://dx.doi.org/10.1063/1.3531761 (3 pages) | Cited 1 time

Online Publication Date: 28 January 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thickness dependence of the integrated Bragg intensities for Czochralski-grown silicon was measured with the characteristic tungsten Kα1-line at 59.3 keV. In contrast to previous experiments the sample is wedge shaped, which allows to take data over a wide range of Pendellösung fringes in one exposure only and without any mechanical movement of the sample. The period length, the oscillation amplitude, and the mean value of the Bragg intensity can be explored to identify the presence of point defects, and the temperature dependence of the period length allows to quantify the thermal Debye-coefficient with high precision.
Show PACS
61.72.J- Point defects and defect clusters
61.66.Bi Elemental solids
63.70.+h Statistical mechanics of lattice vibrations and displacive phase transitions
81.10.Fq Growth from melts; zone melting and refining
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close