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 May 2012

Volume 100, Issue 20, Articles (20xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 100, 203104 (2012); http://dx.doi.org/10.1063/1.3701731 (4 pages)

Z. Y. Jiang, X. X. Jiang, S. Su, X. P. Wei, S. T. Lee, and Y. He
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Enhancement in coupling efficiency from laser to forward hot electrons by conical nanolayered targets

Jinqing Yu (余金清), Weimin Zhou (周维民), Lihua Cao (曹莉华), Zongqing Zhao (赵宗清), Leifeng Cao (曹磊峰), Lianqiang Shan (单连强), Dongxiao Liu (刘东晓), Xiaolin Jin (金晓林), Bin Li (李斌), and Yuqiu Gu (谷渝秋)

Appl. Phys. Lett. 100, 204101 (2012); http://dx.doi.org/10.1063/1.4718735 (3 pages)

Online Publication Date: 15 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To improve the energy coupling efficiency from laser to forward hot electrons, we propose a conical nanolayered target (CNT) and investigate by two-dimensional particle-in-cell simulations. Compared with nanolayered target, the energy coupling efficiency is enhanced from 34% to more than 68%. Detailed simulations indicate that this enhancement is attributed to both oblique incidence and focusing of the conical target. Moreover, CNT collimates the hot electrons better. The proposed target may serve as a new method for enhancing laser to forward hot electrons energy coupling efficiency.
Show PACS
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Silicon germanium tin alloys formed by pulsed laser induced epitaxy

S. Stefanov, J. C. Conde, A. Benedetti, C. Serra, J. Werner, M. Oehme, J. Schulze, D. Buca, B. Holländer, S. Mantl, and S. Chiussi

Appl. Phys. Lett. 100, 204102 (2012); http://dx.doi.org/10.1063/1.4714768 (4 pages)

Online Publication Date: 15 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Pulsed lased induced epitaxy is used to obtain heteroepitaxial Ge1−xSnx and Si1−x−yGexSny alloys with graded composition on Si(001) substrates. The transition from Ge1−xSnx to Si1−x−yGexSny was achieved by varying the number of laser pulses accordingly with the level of intermixing between Si, Ge, and Sn. Melt duration, predicted by numerical methods, is experimentally confirmed by "in-situ" reflectivity measurements and relates, like the end reflectivity value, to the level of intermixing. The possibility to adjust concentration profiles through laser processing of Sn films on virtual germanium buffer layers for lattice engineering of Ge1−xSnx and Si1−x−yGexSny alloys on silicon substrates is demonstrated.
Show PACS
68.55.ag Semiconductors
78.66.Li Other semiconductors
81.15.Fg Pulsed laser ablation deposition

Photothermal cantilever deflection spectroscopy of a photosensitive polymer

Minhyuk Yun, Seonghwan Kim, Dongkyu Lee, Namchul Jung, Inseok Chae, Sangmin Jeon, and Thomas Thundat

Appl. Phys. Lett. 100, 204103 (2012); http://dx.doi.org/10.1063/1.4719521 (4 pages) | Cited 2 times

Online Publication Date: 16 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The mechanical and chemical information of a poly(methyl methacrylate) (PMMA) film on a microcantilever were simultaneously acquired by photothermal cantilever deflection spectroscopy as a function of ultraviolet (UV) irradiation time. Nanomechanical infrared (IR) spectra from the PMMA-coated microcantilever agreed well with the Fourier transform infrared spectroscopy (FTIR) spectra of PMMA on gold-coated silicon wafer. The decreasing intensities of nanomechanical IR peaks represent chemical as well as mechanical information of UV radiation-induced photodegradation processes in the PMMA which cannot be obtained by a conventional FTIR technique. The observed decrease in the resonance frequency of the microcantilever is related to the change in the Young’s modulus of the PMMA under UV exposure.
Show PACS
68.60.Bs Mechanical and acoustical properties
78.30.Jw Organic compounds, polymers
81.40.Jj Elasticity and anelasticity, stress-strain relations
82.50.Hp Processes caused by visible and UV light
62.20.de Elastic moduli
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)

Scaling analysis: Equivalence of convective and radiative heating of levitated droplet

Abhishek Saha, Saptarshi Basu, and Ranganathan Kumar

Appl. Phys. Lett. 100, 204104 (2012); http://dx.doi.org/10.1063/1.4720092 (5 pages) | Cited 5 times

Online Publication Date: 18 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter develops theoretical relationships for equilibrium timescale and temperature scale of a vaporizing droplet in a convective and a radiative environment. The transient temperature normalized by the respective scales exhibits a unified profile for both modes of heating. The analysis allows for the prediction of the required laser flux to show its equivalence in a corresponding heated gas stream. The theoretical equivalence shows good agreement with experiments across a range of droplet sizes. Simple experiments can be conducted in a levitator to extrapolate information in realistic convective environments like combustion and spray drying.
Show PACS
68.03.Fg Evaporation and condensation of liquids
47.70.Fw Chemically reactive flows
47.70.Pq Flames; combustion

Dramatic enhancement of structure-borne wave energy harvesting using an elliptical acoustic mirror

M. Carrara, M. R. Cacan, M. J. Leamy, M. Ruzzene, and A. Erturk

Appl. Phys. Lett. 100, 204105 (2012); http://dx.doi.org/10.1063/1.4719098 (4 pages) | Cited 2 times

Online Publication Date: 18 May 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Broadband structure-borne wave energy harvesting is reported by wave focusing using an elliptical acoustic mirror (EAM). The EAM is formed by an array of cylindrical stubs mounted along a semi-elliptical path on the surface of a plate. The array back-scatters incoming guided waves and focuses them at the focal location where a piezoelectric energy harvester is located. Multiple scattering simulations and experiments illustrate the broadband focusing characteristics of the EAM. More than an order of magnitude improvement in piezoelectric power generation is documented for an EAM-based energy harvester with respect to a free harvester over the 30–70 kHz frequency range.
Show PACS
84.60.-h Direct energy conversion and storage
88.05.-b Energy analysis
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
42.79.Bh Lenses, prisms and mirrors
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close