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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue

28 Dec 2009

Volume 95, Issue 26, Articles (26xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 95, 261901 (2009); http://dx.doi.org/10.1063/1.3268436 (3 pages)

Weiqiang Wang, Richard Clark, Aiichiro Nakano, Rajiv K. Kalia, and Priya Vashishta
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Fast reaction mechanism of a core(Al)-shell (Al2O3) nanoparticle in oxygen

Weiqiang Wang, Richard Clark, Aiichiro Nakano, Rajiv K. Kalia, and Priya Vashishta

Appl. Phys. Lett. 95, 261901 (2009); http://dx.doi.org/10.1063/1.3268436 (3 pages) | Cited 3 times

Online Publication Date: 28 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Atomistic mechanisms of oxidation in a laser flash heated core (Aluminum)-shell (Alumina) nanoparticle are investigated using multimillion-atom molecular dynamics simulations. We find a thermal-to-mechanochemical transition of oxidation mechanism when the initial core temperature is above 6000 K. The transition from thermal diffusion to mechanically enhanced diffusion to ballistic transport is accompanied by a change in the intermediate reaction products from Al rich Al2O to oxygen rich AlO2 clusters. Higher initial temperature of the core causes catastrophic failure of the shell, which provides direct oxidation pathways for core Al, resulting in faster energy release.
Show PACS
82.20.Hf Product distribution
66.30.Xj Thermal diffusivity
82.20.Wt Computational modeling; simulation
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
82.30.-b Specific chemical reactions; reaction mechanisms
73.23.Ad Ballistic transport

The effect of environment on the radial breathing mode of supergrowth single wall carbon nanotubes

P. T. Araujo, C. Fantini, M. M. Lucchese, M. S. Dresselhaus, and A. Jorio

Appl. Phys. Lett. 95, 261902 (2009); http://dx.doi.org/10.1063/1.3276909 (3 pages) | Cited 4 times

Online Publication Date: 28 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
It has been shown that “supergrowth” single wall carbon nanotubes (SWNTs) exhibit a radial breathing mode frequency ωRBM dependence on tube diameter dt given by ωRBM = 227/dt. This result gave rise to two distinct scenarios for SWNTs: one for the supergrowth radial breathing mode and another for all the other samples reported in the literature. Here we show that, by dispersing the supergrowth SWNTs in surfactant or bringing them into interacting bundles, it is possible to merge these two scenarios, where now the supergrowth SWNT properties are similar to all SWNT properties reported so far in the literature.
Show PACS
61.46.Fg Nanotubes
78.67.Ch Nanotubes
81.07.De Nanotubes
78.30.Na Fullerenes and related materials

Spectroscopic evidence for limited carrier hopping interaction in amorphous ZnO thin film

Deok-Yong Cho, Jeong Hwan Kim, Kwang Duk Na, Jaewon Song, Cheol Seong Hwang, Byeong-Gyu Park, Jae-Young Kim, Chul-Hee Min, and Se-Jung Oh

Appl. Phys. Lett. 95, 261903 (2009); http://dx.doi.org/10.1063/1.3275738 (3 pages) | Cited 5 times

Online Publication Date: 28 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electronic structure of amorphous ZnO film (a-ZnO) was examined by O K- and Zn L3-edge x-ray absorption spectroscopy and valence band photoemission spectroscopy. Comparative studies of a-ZnO and a wurtzite ZnO (w-ZnO) revealed a decrease in Zn 4s-O 2p hybridization strength and the localization of Zn 4s band as a consequence of local structural disorder, indicating limited electron hopping interactions in a-ZnO. The 0.1 eV higher Fermi-level of a-ZnO compared to w-ZnO suggests that the electrical properties of a-ZnO are different from those in w-ZnO due to structural disorder, even in the absence of impurities or grain boundaries.
Show PACS
78.66.Hf II-VI semiconductors
79.60.Bm Clean metal, semiconductor, and insulator surfaces
78.70.Dm X-ray absorption spectra
73.61.Ga II-VI semiconductors
72.20.Ee Mobility edges; hopping transport
68.55.ag Semiconductors

Electrical and optical properties of p-type InGaN

B. N. Pantha, A. Sedhain, J. Li, J. Y. Lin, and H. X. Jiang

Appl. Phys. Lett. 95, 261904 (2009); http://dx.doi.org/10.1063/1.3279149 (3 pages) | Cited 11 times

Online Publication Date: 29 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Mg-doped InxGa1−xN alloys were grown by metal organic chemical vapor deposition on semi-insulating c-GaN/sapphire templates. Hall effect measurements showed that Mg-doped InxGa1−xN epilayers are p-type for x up to 0.35. Mg-acceptor levels (EA) as a function of x, (x up to 0.35), were experimentally evaluated from the temperature dependent hole concentration. The observed EA in Mg-doped In0.35Ga0.65N alloys was about 43 meV, which is roughly four times smaller than that in Mg doped GaN. A room temperature resistivity as low as 0.4 Ω cm (with a hole concentration ∼ 5×1018 cm−3 and hole mobility ∼ 3 cm2/V s) was obtained in Mg-doped In0.22Ga0.78N. It was observed that the photoluminescence (PL) intensity associated with the Mg related emission line decreases exponentially with x. The Mg energy levels in InGaN alloys obtained from PL measurements are consistent with those obtained from Hall-effect measurements.
Show PACS
78.66.Fd III-V semiconductors
61.72.uj III-V and II-VI semiconductors
71.55.Eq III-V semiconductors
78.55.Cr III-V semiconductors
73.61.Ey III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Photoluminescence properties of midinfrared dilute nitride InAsN epilayers with/without Sb flux during molecular beam epitaxial growth

Rui Chen, S. Phann, H. D. Sun, Q. Zhuang, A. M. R. Godenir, and A. Krier

Appl. Phys. Lett. 95, 261905 (2009); http://dx.doi.org/10.1063/1.3280861 (3 pages) | Cited 5 times

Online Publication Date: 30 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the comparative studies of photoluminescence (PL) properties of molecular beam epitaxy grown dilute InAsN epilayers with and without antimony (Sb) flux during the growth. Both samples exhibit strong midinfrared (MIR) emission at room temperature, while the sample with Sb flux has much higher intensity. At low temperatures, these samples exhibit totally different PL features in terms of line width, peak position, intensity, and their dependences on temperature and excitation density. Our results clearly indicate that part of Sb atoms serve as a surfactant that effectively improves the optical quality of MIR dilute nitrides.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
68.55.ag Semiconductors
71.20.Nr Semiconductor compounds
71.35.-y Excitons and related phenomena
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Rayleigh surface wave in a piezoelectric wafer with subsurface damage

Xiaoshan Cao, Feng Jin, and Insu Jeon

Appl. Phys. Lett. 95, 261906 (2009); http://dx.doi.org/10.1063/1.3276568 (3 pages) | Cited 1 time

Online Publication Date: 30 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An analytical study is carried out on the propagation of Rayleigh surface waves in a piezoelectric wafer with subsurface damage. The region of subsurface damage is considered to be a functionally graded piezoelectric thin film. The findings show the influence of the gradient parameter, thickness of the region of subsurface damage, and three different types of damage on the properties of surface-wave propagation, including the phase velocity and electromechanical coupling factor. They can provide theoretical guidance in nondestructive evaluation for the analysis of the reliability and durability of electronic devices made of piezoelectric wafers.
Show PACS
77.65.-j Piezoelectricity and electromechanical effects
81.70.-q Methods of materials testing and analysis
68.60.Bs Mechanical and acoustical properties

Temperature dependent structural properties of nanocrystalline SnS structures

M. Devika, N. Koteeswara Reddy, Fernando Patolsky, K. Ramesh, and K. R. Gunasekhar

Appl. Phys. Lett. 95, 261907 (2009); http://dx.doi.org/10.1063/1.3277148 (3 pages) | Cited 6 times

Online Publication Date: 30 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter explores the structural behavior of nanocrystalline tin mono sulfide (SnS) structures with respect to temperature (100–600 K). These studies emphasize that the structural properties of SnS nanocrystalline structures depend on the surrounding temperature. The lattice parameters of SnS nanocrystals slightly varied like their microstructures with the increase of temperature. These changes strongly influence the optical properties of SnS nanostructures. On the other hand, the structures exhibited higher strain ( ∼ 0.44%) than that of microstructured (0.3%) and bulk (0.12%) counterparts. The observed results are discussed under the light of existing concepts and reported.
Show PACS
61.46.Hk Nanocrystals
81.05.Hd Other semiconductors
65.80.-g Thermal properties of small particles, nanocrystals, nanotubes, and other related systems
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters

Toward quantum interference of photons from independent quantum dots

M. Benyoucef, L. Wang, A. Rastelli, and O. G. Schmidt

Appl. Phys. Lett. 95, 261908 (2009); http://dx.doi.org/10.1063/1.3275702 (3 pages) | Cited 4 times

Online Publication Date: 31 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors present steps toward the experimental realization of indistinguishable single photon sources based on independent unstrained GaAs quantum dots (QDs), which are embedded in planar cavities to improve the light collection efficiency. The emission lines of two QDs are brought into resonance and overlapped at a beam splitter. The coherence properties of the emitted photons are investigated by measuring the first-order field correlation function. Despite the fact that the short dephasing time of the selected QDs prevents us to observe quantum interference between the two photons, the approach could be applied to other QDs.
Show PACS
81.07.Ta Quantum dots
81.05.Ea III-V semiconductors
73.21.La Quantum dots
78.67.Hc Quantum dots
78.55.Cr III-V semiconductors
42.79.Fm Reflectors, beam splitters, and deflectors

The influence of As/III pressure ratio on nitrogen nearest-neighbor environments in as-grown GaInNAs quantum wells

R. Kudrawiec, V.-M. Korpijärvi, P. Poloczek, J. Misiewicz, P. Laukkanen, J. Pakarinen, M. Dumitrescu, M. Guina, and M. Pessa

Appl. Phys. Lett. 95, 261909 (2009); http://dx.doi.org/10.1063/1.3275712 (3 pages) | Cited 4 times

Online Publication Date: 31 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The energy fine structure, corresponding to different nitrogen nearest-neighbor environments, was observed in contactless electroreflectance (CER) spectra of as-grown GaInNAs quantum wells (QWs) obtained at various As/III pressure ratios. In the spectral range of the fundamental transition, two CER resonances were detected for samples grown at low As pressures whereas only one CER resonance was observed for samples obtained at higher As pressures. This resonance corresponds to the most favorable nitrogen nearest-neighbor environment in terms of the total crystal energy. It means that the nitrogen nearest-neighbor environment in GaInNAs QWs can be controlled in molecular beam epitaxy process by As/III pressure ratio.
Show PACS
62.50.-p High-pressure effects in solids and liquids
78.20.Jq Electro-optical effects
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.21.Fg Quantum wells
78.66.Fd III-V semiconductors

Second harmonic generation from graphene and graphitic films

Jesse J. Dean and Henry M. van Driel

Appl. Phys. Lett. 95, 261910 (2009); http://dx.doi.org/10.1063/1.3275740 (3 pages) | Cited 9 times

Online Publication Date: 31 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Optical second harmonic generation (SHG) of 800 nm, 150 fs fundamental pulses is observed from exfoliated graphene and multilayer graphitic films mounted on an oxidized silicon (001) substrate. The SHG anisotropy is observed as a sample is rotated about the surface normal. For p-polarized fundamental and SHG light, the isotropic SHG from a graphene layer only slightly interferes with the fourfold symmetric response of the underlying substrate, while other samples show a threefold symmetry characteristic of significant SHG in the multilayer graphitic films. The dominance of the threefold anisotropy is maintained from bilayer graphene to bulk graphite.
Show PACS
78.67.Wj Optical properties of graphene
68.65.Pq Graphene films
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.66.Nk Insulators

Recombination dynamics of photoluminescence in thiol-protected gold nanoclusters

G. W. Shu, C. C. Lin, H. P. Chung, J. L. Shen, C. A. J. Lin, C. H. Lee, W. H. Chang, W. H. Chan, H. H. Wang, H. I. Yeh, C. T. Yuan, and J. Tang

Appl. Phys. Lett. 95, 261911 (2009); http://dx.doi.org/10.1063/1.3277184 (3 pages) | Cited 4 times

Online Publication Date: 31 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Recombination dynamics of photoluminescence (PL) in Au nanoclusters (NCs) with different capping molecules were studied with time-resolved PL. Based on the emission-energy of carrier lifetimes; we suggest that the fast and slow PL decay of Au NCs originates from recombination of the linear Au–S bond and the staple motif, respectively. The effect of carrier localization in Au NCs was found to depend on the capping molecules. The zero-dimensionality of carriers in Au NCs was demonstrated by the temperature dependence of the time-resolved PL.
Show PACS
78.55.Kz Solid organic materials
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.47.jd Time resolved luminescence
61.46.Bc Structure of clusters (e.g., metcars; not fragments of crystals; free or loosely aggregated or loosely attached to a substrate)
78.67.-n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures
73.63.Bd Nanocrystalline materials

Investigation of compositional inhomogeneities in complex polycrystalline Cu(In,Ga)Se2 layers for solar cells

X. Fontané, V. Izquierdo-Roca, L. Calvo-Barrio, A. Pérez-Rodríguez, J. R. Morante, Dominik Guettler, A. Eicke, and A. N. Tiwari

Appl. Phys. Lett. 95, 261912 (2009); http://dx.doi.org/10.1063/1.3280049 (3 pages)

Online Publication Date: 31 December 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In-depth resolved composition inhomogeneities of polycrystalline Cu(In,Ga)Se2 (CIGS) complex layers for high efficiency solar cells were investigated with Raman scattering measurements. In-depth resolved analysis of the frequency of the main CIGS Raman mode in the spectra measured after sputtering of the layers at different depths lead to identification of different compositions across the layer thickness. These data are in good agreement at both qualitative and quantitative levels with the in-depth resolved composition analysis of the samples by sputtered neutral mass spectroscopy. In addition, Raman measurements also allow detection of additional phases as ordered vacancy compounds.
Show PACS
78.30.Hv Other nonmetallic inorganics
68.55.ag Semiconductors
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close