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

18 Jun 2001

Volume 78, Issue 25, pp. 3927-4046

Return to All Sections
back to top
RSS Feeds

Synthesis of extremely small InP quantum dots and electronic coupling in their disordered solid films

Olga I. Mićić, S. P. Ahrenkiel, and Arthur J. Nozik

Appl. Phys. Lett. 78, 4022 (2001); http://dx.doi.org/10.1063/1.1379990 (3 pages) | Cited 51 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Extremely small colloidal InP quantum dots (QDs) with diameters ranging from 15 to 23 Å were synthesized, and the optical properties of close-packed arrays of these dots were studied. The isolated QDs in dilute colloidal solution exhibit pronounced discrete absorption spectra, indicating a narrow size distribution. The absorption spectra of close-packed solids of ∼18 Å diameter QDs with interdot spacings of 9 and 18 Å show that the absorption onsets and excitonic peaks are, respectively, redshifted and broadened in going from dilute solution to close-packed solids. These results can be explained by electron delocalization in disordered close-packed solids; the spacing of electronic levels in the QDs is reduced and produces a redshift in the absorption spectra. © 2001 American Institute of Physics.
Show PACS
81.07.Ta Quantum dots
78.67.Hc Quantum dots
73.21.La Quantum dots
78.40.Fy Semiconductors
81.16.Be Chemical synthesis methods
68.65.Hb Quantum dots (patterned in quantum wells)
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
73.20.Jc Delocalization processes

Optical transitions and excitonic recombination in InAs/InP self-assembled quantum wires

Benito Alén, Juan Martínez-Pastor, Alberto García-Cristobal, Luisa González, and Jorge M. García

Appl. Phys. Lett. 78, 4025 (2001); http://dx.doi.org/10.1063/1.1379991 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
InAs self-assembled quantum wire structures have been grown on InP substrates and studied by means of photoluminescence and polarized-light absorption measurements. According to our calculations, the observed optical transitions in each sample are consistent with wires of different heights, namely from 6 to 13 monolayers. The nonradiative mechanism limiting the emission intensity at room temperature is related to thermal escape of carriers out of the wires. © 2001 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.67.Lt Quantum wires
78.55.Cr III-V semiconductors
81.05.Ea III-V semiconductors
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
73.21.Hb Quantum wires

Nucleation and growth of well-aligned, uniform-sized carbon nanotubes by microwave plasma chemical vapor depositon

N. Wang and B. D. Yao

Appl. Phys. Lett. 78, 4028 (2001); http://dx.doi.org/10.1063/1.1381036 (3 pages) | Cited 22 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The nucleation and growth of carbon nanotubes assisted by microwave plasma on metal surfaces have been observed by transmission electron microscopy. Microwave plasma generated nanoparticles of various sizes on metal surfaces. Initially, the nanoparticles were embedded in an amorphous carbon layer and led to the formation of carbon tube nuclei. At the early stage of growth, the carbon tube diameters ranged from 10 to 100 nm. Carbon tubes with diameters of 40–50 nm had a high growth rate in the vertical direction, resulting in the formation of tube arrays. © 2001 American Institute of Physics.
Show PACS
81.07.De Nanotubes
61.46.-w Structure of nanoscale materials
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
52.77.Dq Plasma-based ion implantation and deposition
68.55.A- Nucleation and growth
79.70.+q Field emission, ionization, evaporation, and desorption
85.45.Db Field emitters and arrays, cold electron emitters

Force based displacement measurement in micromechanical devices

S. J. O’Shea, C. K. Ng, Y. Y. Tan, Y. Xu, E. H. Tay, B. L. Chua, N. C. Tien, X. S. Tang, and W. T. Chen

Appl. Phys. Lett. 78, 4031 (2001); http://dx.doi.org/10.1063/1.1380398 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate how force detection methods based on atomic force microscopy can be used to measure displacement in micromechanical devices. We show the operation of a simple microfabricated accelerometer, the proof mass of which incorporates a tip which can be moved towards an opposing surface. Both noncontact operation using long range electrostatic forces and tapping mode operation are demonstrated. The displacement sensitivity of the present device using feedback to control the tip-surface separation is approximately 1 nm. © 2001 American Institute of Physics.
Show PACS
07.10.Cm Micromechanical devices and systems
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)
07.79.Lh Atomic force microscopes
07.10.Pz Instruments for strain, force, and torque
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close