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

14 Nov 2005

Volume 87, Issue 20, Articles (20xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 87, 202104 (2005); http://dx.doi.org/10.1063/1.2132071 (3 pages)

J. A. Keogh, K. Das Gupta, H. E. Beere, D. A. Ritchie, and M. Pepper
Enlarge Image | Read More
Page 1 of 4 Pages Next Page | Jump to Page
back to top
RSS Feeds

Effect of gain localization in circular-grating distributed feedback lasers

G. A. Turnbull, A. Carleton, A. Tahraouhi, T. F. Krauss, I. D. W. Samuel, G. F. Barlow, and K. A. Shore

Appl. Phys. Lett. 87, 201101 (2005); http://dx.doi.org/10.1063/1.2120915 (3 pages) | Cited 9 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We explore the influence of gain localization on the lasing performance of circular-grating distributed feedback (CDFB) lasers. The effect is studied in an optically pumped CDFB laser resonator based on a waveguide of the conjugated polymer poly[2-methoxy-5-(2′ethylhexyloxy)-1,4-phenylene vinylene]. Variations in lasing threshold and slope efficiency are determined as a function of the radius of the optical excitation. The experimental lasing results are compared with predictions from a theoretical analysis based on an adaptation of the transfer matrix method. We find that a strong localization of the gain near the center of the CDFB laser can lead to both a substantial reduction in threshold and increase in output efficiency. As the excitation radius changes from a 90 to a 15 μm radius, the threshold energy decreases from 5.3 to 0.29 nJ, and the surface-emitted output efficiency increases by an order of magnitude. A simple model is developed that confirms that the significant reduction in threshold can be explained by an enhanced overlap of the population inversion with the resonant mode.
Show PACS
42.55.Xi Diode-pumped lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.70.Jk Polymers and organics
42.70.Hj Laser materials

Sample heating in near-field scanning optical microscopy

Elizabeth S. Erickson and Robert C. Dunn

Appl. Phys. Lett. 87, 201102 (2005); http://dx.doi.org/10.1063/1.2130388 (3 pages) | Cited 4 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Heating near the aperture of aluminum coated, fiber optic near-field scanning optical microscopy probes was studied as a function of input and output powers. Using the shear-force feedback method, near-field probes were positioned nanometers above a thermochromic polymer and spectra were recorded as the input power was varied. Excitation at 405 nm of a thin polymer film incorporating perylene and N-allyl-N-methylaniline leads to dual emission peaks in the spectra. The relative peak intensity is temperature sensitive leading to a ratiometric measurement, which avoids complications based solely on intensity. Using this method, we find that the proximal end of typical near-field probes modestly increase in temperature to 40–45 °C at output powers of a few nanowatts (input power of ∼ 0.15 mW). This increases to 55–65 °C at higher output powers of 50 nW or greater (input power of ∼ 2–4 mW). Thermal heating of the probe at higher powers leads to probe elongation, which limits the heating experienced by the sample.
Show PACS
07.79.Fc Near-field scanning optical microscopes
81.40.Gh Other heat and thermomechanical treatments
78.66.Qn Polymers; organic compounds
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity

Negative luminescence of long-wavelength InAs/GaSb superlattice photodiodes

Darin Hoffman, Andrew Hood, Yajun Wei, Aaron Gin, Frank Fuchs, and Manijeh Razeghi

Appl. Phys. Lett. 87, 201103 (2005); http://dx.doi.org/10.1063/1.2130536 (3 pages) | Cited 5 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electrically pumped emission behavior of binary type-II InAs/GaSb superlattice photodiodes has been studied in the spectral range between 8 μm and 13 μm. With a radiometric calibration of the experimental setup, the internal and external quantum efficiency has been determined in the temperature range between 80 K and 300 K for both, the negative and positive luminescence. The negative luminescence efficiency approaches values as high as 35% without antireflection coating. The temperature dependence of the internal quantum efficiency near zero-bias voltage allows for the determination of the electron-hole-electron Auger recombination coefficient of Γn = 1×1024 cm6 s−1.
Show PACS
85.60.Dw Photodiodes; phototransistors; photoresistors

Wavelength-codified fiber laser hydrogen detector

A. Ortigosa-Blanch, A. Díez, A. González-Segura, J. L. Cruz, and M. V. Andrés

Appl. Phys. Lett. 87, 201104 (2005); http://dx.doi.org/10.1063/1.2130531 (3 pages) | Cited 6 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a scheme for an optical hydrogen detector that codifies the information in wavelength. The system is based on an erbium-doped fiber laser with two coupled cavities and a Palladium-coated tapered fiber within one of the laser cavities. The tapered fiber acts as the hydrogen-sensing element. When the sensing element is exposed to a hydrogen atmosphere, its attenuation decreases changing the cavity losses. This change leads the system to switch lasing from the wavelength of the auxiliary cavity to the characteristic wavelength of the cavity which contains the sensing element. The detection level can be shifted by adjusting the reflective elements of the cavity containing the sensing element.
Show PACS
42.81.Pa Sensors, gyros
42.79.Qx Range finders, remote sensing devices; laser Doppler velocimeters, SAR, and LIDAR
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
42.55.Wd Fiber lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

On the role of dislocation loops in silicon light emitting diodes

M. A. Lourenço, M. Milosavljević, R. M. Gwilliam, K. P. Homewood, and G. Shao

Appl. Phys. Lett. 87, 201105 (2005); http://dx.doi.org/10.1063/1.2130533 (3 pages) | Cited 10 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The role of boron-induced dislocation loops on the suppression of the luminescence thermal quenching in silicon-based light-emitting diodes is investigated here. Luminescence measurements and cross-sectional transmission-electron-microscopy images from devices fabricated by boron implantation into crystalline silicon, and into a pre-amorphized substrate, to prevent the boron-induced loops formation, were compared. The results show that, in the devices incorporating dislocation loops between the depletion region and sample surface (the boron induced loops), the thermal quenching has been completely eliminated, in contrast with devices fabricated from the pre-amorphized substrate where strong thermal quenching is still observed.
Show PACS
85.60.Jb Light-emitting devices

Fringing-field minimization in liquid-crystal-based high-resolution switchable gratings

Lanlan Gu, Xiaonan Chen, Wei Jiang, Brie Howley, and Ray T. Chen

Appl. Phys. Lett. 87, 201106 (2005); http://dx.doi.org/10.1063/1.2130729 (3 pages) | Cited 12 times

Online Publication Date: 9 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A liquid-crystal (LC)-based high-resolution switchable grating is proposed by using a double-sided structure, where striped electrodes are patterned on both sides of the LC cell. A unique biasing configuration is employed to successfully minimize the distortion of the LC director profile due to the fringing-field effects under two-dimensional electric fields. A first order diffraction angle of 14.5° with a diffraction efficiency of 33% for transmission light at 1.55 μm is experimentally achieved. This result approaches the theoretical upper limit of 33.8% for a sinusoidal phase grating. The device efficiency is enhanced 80 times compared to a conventional single-sided device. Experimental results indicate the tolerance of electrode misalignment is 2 μm.
Show PACS
42.79.Kr Display devices, liquid-crystal devices
42.79.Dj Gratings
42.65.Pc Optical bistability, multistability, and switching, including local field effects

Refractometric sensors based on microsphere resonators

Niranjan M. Hanumegowda, Caleb J. Stica, Bijal C. Patel, Ian White, and Xudong Fan

Appl. Phys. Lett. 87, 201107 (2005); http://dx.doi.org/10.1063/1.2132076 (3 pages) | Cited 71 times

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed a highly sensitive refractometric sensor based on fused silica microsphere resonators. The spectral position of the whispering gallery mode (WGM) of a sphere shifts in response to the refractive index change in the surrounding medium. The strong light-matter interaction due to the extremely high Q factor associated with the WGM results in a sensitivity of approximately 30 nm/RIU (refractive index units). This, together with the high spectral resolution of our sensor system ( ∼ 0.01 pm), yields a detection limit of refractive index change on the order of 10−7 RIU. Theoretical calculation is also performed and agrees well with the experimental data.
Show PACS
07.60.Hv Refractometers and reflectometers
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

Nonlinear all-optical GaN/AlGaN multi-quantum-well devices for 100 Gb/s applications at λ = 1.55 μm

Greg Sun, Jacob B. Khurgin, and Richard A. Soref

Appl. Phys. Lett. 87, 201108 (2005); http://dx.doi.org/10.1063/1.2132084 (3 pages) | Cited 8 times

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using quantum-mechanical analysis, a strain-balanced stack of coupled GaN/AlGaN quantum wells has been engineered for bandwidth-optimized all-optical switching at low switching powers. Intersubband transitions between three conduction subbands provide the basis for the large, fast, nonlinear optical response. Optimized performance for a given symbol rate is obtained by engineering the response time and nonlinear phase shift.
Show PACS
42.65.Pc Optical bistability, multistability, and switching, including local field effects
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
42.79.Sz Optical communication systems, multiplexers, and demultiplexers

Tuning and optical study of the ΓX and ΓL photonic pseudogaps in opals

P. D. García, J. F. Galisteo-López, and C. López

Appl. Phys. Lett. 87, 201109 (2005); http://dx.doi.org/10.1063/1.2132068 (3 pages) | Cited 13 times

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter we demonstrate a method to tune and optically investigate the two highest-symmetry pseudogaps in artificial opals which occur at the L an X points of the Brillouin zone and correspond to propagation along the (111) and (100) crystallographic directions, respectively. In particular we show that in artificial opals the gap at the X point, which is closed for bare opals, can be opened by controlled infiltration with a high refractive index material such as ZnO. To prove this we take advantage of the fact that, in artificial opals grown by the vertical deposition method, regions with both (100) and (111) orientations of the face centerd cubic lattice occur naturally.
Show PACS
42.70.Qs Photonic bandgap materials
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Temperature-dependent luminescence of InP quantum dots coupled with an InGaP quantum well and of InP quantum dots in a quantum well

X. B. Zhang, J. H. Ryou, R. D. Dupuis, G. Walter, and N. Holonyak

Appl. Phys. Lett. 87, 201110 (2005); http://dx.doi.org/10.1063/1.2132529 (3 pages) | Cited 1 time

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the temperature-dependent cathodoluminescence (CL) properties of (1) InP/InAlGaP quantum dots (QDs) coupled to an InGaP quantum well (QW) through a thin InAlGaP barrier (or simply QW+QD), (2) InP QDs grown directly in the well (DWELL), and (3) a reference sample InP/InAlGaP QDs. We found that with an increase in temperature, the CL peak of the reference sample shows a large redshift compared with the band gap shift of InP. This large redshift is due to the thermally activated carriers transferred from small QDs to large ones. Within the temperature range studied, this redshift of the CL peak is much larger in DWELL but is much smaller, and in some temperature range, the energy of CL peak is independent of temperature for QW+QD samples. We believe that the temperature-insensitive emission energy observed in QW+QD is caused by (1) thermalization of hot carriers in the QW and (2) nonuniform tensile strain in the QW created by the varying sizes of QDs on top of the QW.
Show PACS
78.60.Hk Cathodoluminescence, ionoluminescence
78.67.Lt Quantum wires
78.67.De Quantum wells
78.20.N- Thermo-optic effects
78.20.nb Photothermal effects
72.20.Ht High-field and nonlinear effects

Gap soliton memory in a resonant photonic crystal

Igor V. Mel’nikov and J. Stewart Aitchison

Appl. Phys. Lett. 87, 201111 (2005); http://dx.doi.org/10.1063/1.2132070 (3 pages) | Cited 12 times

Online Publication Date: 11 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We consider the interaction of two coherent optical pulses in a one-dimensional, resonant photonic crystal which includes a defect produced by a coherent pump. Using numerical methods, the defect is shown to provide a selective reversible trap for a gap soliton mediated by the long-range coupling. This opens up new opportunities for signal transmission control, light localization and a simple one bit optical memory.
Show PACS
42.79.Vb Optical storage systems, optical disks
42.65.Tg Optical solitons; nonlinear guided waves
42.70.Qs Photonic bandgap materials

Supression of carrier recombination in semiconductor lasers by phase-space filling

J. Hader, J. V. Moloney, and S. W. Koch

Appl. Phys. Lett. 87, 201112 (2005); http://dx.doi.org/10.1063/1.2132524 (3 pages) | Cited 7 times

Online Publication Date: 11 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A fully microscopic model is used to calculate the carrier losses in semiconductor lasers due to Auger recombination and spontaneous emission. The results show that the commonly assumed power-law dependencies of these loss processes on the plasma density break down already below the transparency point. Most significantly, the density dependent increase of the spontaneous emission changes from quadratic to linear, while the increase of the Auger recombination is reduced from cubic to approximately quadratic or even less.
Show PACS
42.55.Px Semiconductor lasers; laser diodes

32 nm digitally tunable laser diode with a 0.58 nm wavelength grid using a vertically integrated Mach-Zehnder interferometer

T. Jacke, R. Todt, R. Meyer, and M.-C. Amann

Appl. Phys. Lett. 87, 201113 (2005); http://dx.doi.org/10.1063/1.2132531 (3 pages)

Online Publication Date: 11 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A forward-coupling laser is presented that uses a monolithically integrated Mach-Zehnder interferometer (MZI) inside the laser cavity for discrete wide wavelength tuning. The electronically tunable MZI filter selects one individual mode out of the discrete Fabry-Pérot spectrum. The emission wavelength is thereby controlled by one current only. Internal reflections are a key issue for all forward coupling lasers as they limit the number of accessible modes. Employing an appropriate optical resonator design, the present laser structure overcomes this drawback and demonstrates full and regular wavelength accessibility across the free spectral range of 32 nm.
Show PACS
42.60.Fc Modulation, tuning, and mode locking
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
07.60.Ly Interferometers
42.82.-m Integrated optics

Electromagnetic wave transmission through subwavelength metallic meshes sandwiched between split rings

Bo Hou, He Wen, Yang Leng, and Weijia Wen

Appl. Phys. Lett. 87, 201114 (2005); http://dx.doi.org/10.1063/1.2133915 (3 pages) | Cited 9 times

Online Publication Date: 11 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the extraordinary enhanced transmission of microwaves through a subwavelength metallic mesh sandwiched between two identical split-ring arrays. Such split-rings/metallic mesh/split-rings structure demonstrates some unique electromagnetic (EM) characteristics. It is found that the transmittances of EM wave are significantly enhanced at some frequencies near the stop bands of the split rings. The theoretical simulation indicates that two different physical mechanisms dominate those transmissions: negative refractive index effect and electromagnetic wave tunneling when EM wave penetrates through negative permittivity media sandwiched between two high permittivity slabs.
Show PACS
41.20.Jb Electromagnetic wave propagation; radiowave propagation
84.40.-x Radiowave and microwave (including millimeter wave) technology
back to top
RSS Feeds

Expansion of the plasma stability range in radio-frequency atmospheric-pressure glow discharges

J. J. Shi and M. G. Kong

Appl. Phys. Lett. 87, 201501 (2005); http://dx.doi.org/10.1063/1.2128691 (3 pages) | Cited 35 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Reliable applications of atmospheric-pressure glow discharges (APGDs) depend critically on their plasma stability. A common technique of ensuring APGD stability is to keep their operation well within their stability range by decreasing their discharge current. However, this reduces the achievable densities of the reactive plasma species and, thereby, compromises the application efficiency. In this letter, the use of high excitation frequencies in radio-frequency APGD is shown to substantially expand their stability range. It is also demonstrated that high-frequency operation introduces an added benefit of higher electron energy and greater electron density, thus enabling more abundant reactive plasma species and improved application efficiency.
Show PACS
52.35.Qz Microinstabilities (ion-acoustic, two-stream, loss-cone, beam-plasma, drift, ion- or electron-cyclotron, etc.)
52.80.Hc Glow; corona
52.80.Pi High-frequency and RF discharges
52.25.Fi Transport properties

Chirped pulse compression in nonuniform plasma Bragg gratings

Hui-Chun Wu, Zheng-Ming Sheng, and Jie Zhang

Appl. Phys. Lett. 87, 201502 (2005); http://dx.doi.org/10.1063/1.2132074 (3 pages) | Cited 14 times

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A nonuniform plasma Bragg grating with a monotonically increasing density-modulation profile can be naturally produced by two Gaussian laser pulses counterpropagating through a homogeneous plasma slab. Such a plasma grating exhibits a nonuniform photonic band gap with a monotonically increasing width. It can be used to compress a positively or negatively chirped pulse. Particle-in-cell simulations show that the compressed pulse has nearly no energy loss and the compression efficiency can exceed 90%.
Show PACS
52.38.-r Laser-plasma interactions
42.79.Dj Gratings
42.70.Qs Photonic bandgap materials
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
52.65.Rr Particle-in-cell method

Electron and ion sheath effects on a microwave “hairpin” probe

F. A. Haas, J. Al-Kuzee, and N. St. J. Braithwaite

Appl. Phys. Lett. 87, 201503 (2005); http://dx.doi.org/10.1063/1.2131196 (3 pages) | Cited 10 times

Online Publication Date: 10 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A microwave measurement of electron density in low-pressure plasmas can be based on a hairpin probe. The hairpin forms a transmission line that supports a quarter-wavelength standing wave. The resonance is related to the relative permittivity of the surroundings, and hence, in a plasma, electron density can be evaluated. For improved fidelity, a general model is developed to include the effects of positive and negative space-charge sheaths formed around the hairpin wires. The former tends to lower the resonance, whereas the latter tends to raise it initially. This is qualitatively in agreement with experiments in dc argon plasmas.
Show PACS
52.40.Kh Plasma sheaths
52.70.Gw Radio-frequency and microwave measurements
52.25.Mq Dielectric properties
back to top
RSS Feeds

H enhancement of N vacancy migration in GaN

R. R. Wixom and A. F. Wright

Appl. Phys. Lett. 87, 201901 (2005); http://dx.doi.org/10.1063/1.2130389 (3 pages) | Cited 3 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have used density functional theory to investigate diffusion of VN+ in the presence of H+. Optimal migration pathways were determined using the climbing image nudged elastic band and directed dimer methods. Our calculations indicate that the rate-limiting barrier for VN+ migration will be reduced by 0.58 eV by interplay with H+, which will enhance migration by more than an order of magnitude at typical GaN growth temperatures.
Show PACS
66.30.Lw Diffusion of other defects
61.72.J- Point defects and defect clusters

Thermoelectric properties and figure of merit of a Te-doped InSb bulk single crystal

Shigeo Yamaguchi, Takayuki Matsumoto, Jun Yamazaki, Nakaba Kaiwa, and Atsushi Yamamoto

Appl. Phys. Lett. 87, 201902 (2005); http://dx.doi.org/10.1063/1.2130390 (3 pages) | Cited 16 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We studied the temperature dependence of the thermoelectric properties of a Te-doped InSb bulk single crystal. The temperature was in the range from 10 to 723 K. We analyzed the scattering mechanisms throughout the whole temperature range and found that above 50 K, scattering by polar optical phonons was dominant. The maximum value of the dimensionless figure of merit was 0.6 at 673 K. The load characteristics of the sample were an open output voltage of 28 mV and a maximum output power of 216 μW at a temperature difference of 195 K.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
72.80.Ey III-V and II-VI semiconductors
63.20.-e Phonons in crystal lattices

Interstitial injection in silicon after high-dose, low-energy arsenic implantation and annealing

C. Tsamis, D. Skarlatos, G. BenAssayag, A. Claverie, W. Lerch, and V. Valamontes

Appl. Phys. Lett. 87, 201903 (2005); http://dx.doi.org/10.1063/1.2130397 (3 pages) | Cited 3 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this work, we investigate the interstitial injection into the silicon lattice due to high-dose, low-energy arsenic implantation. The approach consists in monitoring the diffusion of the arsenic profile as well as of the boron profile in buried δ-doped layers, when amounts of the as-implanted arsenic profile are removed by low-temperature wet silicon etching. The experimental results indicate that the contribution of the implantation damage to the transient enhanced diffusion of boron, and thus the interstitial injection, is not the main one. On the contrary, interstitial generation due to arsenic clustering seems to be more important for the present conditions.
Show PACS
61.72.uf Ge and Si
61.72.J- Point defects and defect clusters
61.80.Jh Ion radiation effects
61.72.Cc Kinetics of defect formation and annealing
66.30.-h Diffusion in solids
81.65.Cf Surface cleaning, etching, patterning

Determination of stress versus strain relationship and other thermomechanical properties of thin films

W. M. Huang, Y. Y. Hu, and L. An

Appl. Phys. Lett. 87, 201904 (2005); http://dx.doi.org/10.1063/1.2130710 (3 pages) | Cited 6 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
There are numerous applications of various types of thin films at present, partially driven by the current trend toward micron∕submicron scaled devices. Hence, simple approaches for characterizing the thermomechanical properties of thin films are highly in demand. Here, we propose a few generic approaches to characterize the thermomechanical properties of thin films atop of an elastic substrate. These approaches utilize only conventional techniques for testing. Additionally, they are applicable to materials of nonlinear mechanical behavior and∕or with temperature dependent properties. The analytical solutions of very thin films are presented.
Show PACS
68.60.Bs Mechanical and acoustical properties
46.35.+z Viscoelasticity, plasticity, viscoplasticity

Lattice location and thermal evolution of small B complexes in crystalline Si

L. Romano, A. M. Piro, S. Mirabella, M. G. Grimaldi, and E. Rimini

Appl. Phys. Lett. 87, 201905 (2005); http://dx.doi.org/10.1063/1.2130719 (3 pages) | Cited 5 times

Online Publication Date: 7 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The lattice location of B in Si has been investigated by channelling analyses using nuclear reactions (650 keV proton beam, math(p,α)math). The formation at room temperature of a specific, small B complex in presence of an excess of point defects has been inferred. In particular, B implanted in Si or B substitutional dissolved in Si and irradiated with proton beam form a unique B complex with B atoms not randomly located. The angular scans along the ⟨100⟩ and ⟨110⟩ axes are compatible with B–B pairs aligned along the ⟨100⟩ axis. The thermal annealing in the 200–950 °C range of the B complexes, analyzed by lattice location and carrier concentration measurements, depends on the residual defect density in the lattice. The B complexes dissolve at low temperature if no excess of Si self-interstitials (Is) exists or they evolve into large B clusters and then dissolve at high temperature if Is supersaturation holds.
Show PACS
61.72.uf Ge and Si
61.72.J- Point defects and defect clusters
61.80.Jh Ion radiation effects
61.82.Fk Semiconductors
61.72.Cc Kinetics of defect formation and annealing
61.85.+p Channeling phenomena (blocking, energy loss, etc.)

Titanium fullerenoid oxides

C. Ducati, E. Barborini, G. Bongiorno, S. Vinati, P. Milani, and P. A. Midgley

Appl. Phys. Lett. 87, 201906 (2005); http://dx.doi.org/10.1063/1.2128489 (3 pages) | Cited 7 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanostructured titanium oxide films synthesized by supersonic cluster beam deposition were analyzed by high-resolution transmission electron microscopy. Nanoparticles were produced in a pulsed microplasma cluster source in the presence of He or helium-oxygen mixture as carrier gas. While films grown using He consist only of rutile and anatase TiO2 nanocrystals formed upon exposure to air, films grown with a He/O mixture also contain isolated TiOx cages that closely resemble carbon fullerenes. The diameter of the cages ranges from about 0.9 to 2.7 nm. A fraction of the cages have irregular shapes, possibly induced by oxygen vacancies. The TiOx fullerenoids grow in the gas phase, in a narrow temperature/pressure range within the cluster source, and are preserved through low-energy deposition.
Show PACS
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
81.05.ub Fullerenes and related materials
61.46.-w Structure of nanoscale materials

Double-transducer structure for picosecond ultrasound generation

Ta-Ching Li, Nen-Wen Pu, Ben-Je Lwo, En-Yea Pan, and Chin-Hsing Kao

Appl. Phys. Lett. 87, 201907 (2005); http://dx.doi.org/10.1063/1.2128692 (3 pages)

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a double-transducer technique for more effective generation of picosecond acoustic waves. A tungsten layer, which is buried under a transparent film and a thin top metal transducer, plays the role of a bottom laser-acoustic transducer as well as a high-impedance acoustic reflector. The pulse shape and the induced piezoreflectance response of the acoustic wave launched by the bottom transducer are different from the conventional top transducer. The effect of the bottom transducer depends on the thicknesses and optical constants of the top transducer and the transparent film. The accuracy of velocity measurement can be raised owing to more efficient energy utilization, halved pulse broadening and attenuation of the tungsten-launched waves, and the added signatures on the reflectance curve.
Show PACS
43.38.Ar
43.35.Yb
43.58.Dj
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Residual strain around a step edge of artificial Al/Si(111)-7×7 nanocluster

Zhanwei Liu, Huimin Xie, Daining Fang, Fulong Dai, Qikun Xue, Hong Liu, and Jinfeng Jia

Appl. Phys. Lett. 87, 201908 (2005); http://dx.doi.org/10.1063/1.2130722 (3 pages) | Cited 9 times

Online Publication Date: 8 November 2005

Full Text: Read Online (HTML) | Download PDF

Show Abstract
During artificial Al/Si(111)-7×7 nanocluster fabrication by using surface-mediated clustering, original step with an atomically straight edge becomes curved and irregular because of stronger attractive interaction between Al atoms and Si atoms. Surface residual strain around step edges has been studied by using digital geometric phase technique. The results show that the residual strain is compressive and there is larger compressive stress near both of the up and down step edges.
Show PACS
62.25.-g Mechanical properties of nanoscale systems
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity
Page 1 of 4 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close