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

16 Sep 2002

Volume 81, Issue 12, pp. 2145-2305

Return to All Sections
back to top
RSS Feeds

Effect of MgZnO-layer capping on optical properties of ZnO epitaxial layers

T. Makino, K. Tamura, C. H. Chia, Y. Segawa, M. Kawasaki, A. Ohtomo, and H. Koinuma

Appl. Phys. Lett. 81, 2172 (2002); http://dx.doi.org/10.1063/1.1506783 (3 pages) | Cited 20 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoluminescence (PL) and reflectivity spectra of ZnO epilayers capped with MgxZn1−xO layers (up to x = 0.36) are reported. These capped films were epitaxially grown on lattice-matched ScAlMgO4 substrates by laser molecular-beam epitaxy. A photoluminescence spectrum from the ZnO layer taken at 5 K shows emission bands at 3.389, 3.376, and 3.362 eV. The two higher bands are due to A- and B-free exciton emissions and the lowest band is due to emission of a neutral-acceptor bound exciton (I6). The linewidth of the I6 emission in our uncapped sample (0.8 meV) is significantly smaller than that in the capped one (6 meV). This is probably due to strain applied across the ZnO layer because of the difference in lattice constant between the two layers. The spectral assignment of the free exciton emissions is strengthened by a comparison with a temperature-dependent PL study and a reflectivity study. With an increase in temperature, the intensity of the bound exciton emission line decreased drastically and became comparable to that of free exciton lines. Free exciton emissions are already detectable at the liquid He temperature for the capped samples, which is never achieved in the uncapped ones grown under identical conditions. This indicates the high degree of purity of the capped films. © 2002 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
78.55.Et II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.15.Fg Pulsed laser ablation deposition
71.35.Cc Intrinsic properties of excitons; optical absorption spectra

Infrared dielectric response function of strained In1−xGaxAs/InP epilayers

G. Yu, N. L. Rowell, D. J. Lockwood, and P. J. Poole

Appl. Phys. Lett. 81, 2175 (2002); http://dx.doi.org/10.1063/1.1506006 (3 pages) | Cited 11 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
Polarized infrared reflectivity measurements have been performed on strained In1−xGaxAs epilayers grown by chemical beam epitaxy on semi-insulating InP(100) with x varied from 0.314 to 0.556. Fitting of the reflectance spectra yielded excellent agreement with three longitudinal and transverse optical phonon pairs, corresponding to GaAs-like, disorder-induced, and InAs-like modes. The dielectric response function and phonon frequency dependences for all modes were obtained versus Ga fraction. © 2002 American Institute of Physics.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons
63.20.D- Phonon states and bands, normal modes, and phonon dispersion
78.66.Fd III-V semiconductors
81.05.Ea III-V semiconductors
78.30.Fs III-V and II-VI semiconductors

Properties of AlxGa1−xN layers grown by plasma-assisted molecular-beam epitaxy under Ga-rich conditions

L. He, M. A. Reshchikov, F. Yun, D. Huang, T. King, and H. Morkoç

Appl. Phys. Lett. 81, 2178 (2002); http://dx.doi.org/10.1063/1.1506206 (3 pages) | Cited 8 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
AlxGa1−xN films were grown by plasma-assisted molecular-beam epitaxy on (0001) sapphire substrates under Ga-rich conditions. To control the AlxGa1−xN composition over the entire range, the Al and Ga arrival rates were fixed while the nitrogen arrival rate was varied. We have found that the Al fraction increased with decreasing N flow due to preferentially favorable bonding of Al and N over Ga and N. Consequently, the growth rate decreased as the Al mole fraction increased. A photoluminescence quantum efficiency at 15 K was markedly higher for the AlxGa1−xN layers grown under Ga-rich conditions (3%–48%) compared to the layers grown under N-rich conditions (1%–10%), indicating much reduced nonradiative recombination in samples grown under Ga-rich conditions. © 2002 American Institute of Physics.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.05.Ea III-V semiconductors
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
73.61.Ey III-V semiconductors
68.55.-a Thin film structure and morphology
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Growth of SiCAlN on Si(111) via a crystalline oxide interface

John Tolle, R. Roucka, P. A. Crozier, A. V. G Chizmeshya, I. S. T. Tsong, and J. Kouvetakis

Appl. Phys. Lett. 81, 2181 (2002); http://dx.doi.org/10.1063/1.1507358 (3 pages) | Cited 3 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Growth of single-phase SiCAlN epitaxial films with the 2H–wurtzite structure is conducted directly on Si(111) despite the structural differences and large lattice mismatch (19%) between the two materials. Commensurate heteroepitaxy is facilitated by the conversion of native and thermally grown SiO2 layers on Si(111) into crystalline oxides by in situ reactions of the layers with Al atoms and the H3SiCN precursor, forming coherent interfaces with the Si substrate and the film. High-resolution transmission electron microscopy and electron energy-loss spectroscopy show that the amorphous SiO2 films are entirely transformed into a crystalline Si–Al–O–N framework in registry with the Si(111) surface. This crystalline interface acts as a template for nucleation and growth of epitaxial SiCAlN. Integration of wide-band-gap semiconductors with Si is readily achieved by this process. © 2002 American Institute of Physics.
Show PACS
68.55.A- Nucleation and growth
68.35.Ct Interface structure and roughness
68.55.-a Thin film structure and morphology
68.37.Lp Transmission electron microscopy (TEM)
79.20.Uv Electron energy loss spectroscopy

Determination of recombination parameters of phosphors from cathodoluminescent characteristics

Sergey A. Bukesov and Duk Y. Jeon

Appl. Phys. Lett. 81, 2184 (2002); http://dx.doi.org/10.1063/1.1508170 (3 pages) | Cited 7 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple method to determine recombination parameters of polycrystalline phosphor materials is proposed based on a comparison of a theoretical prediction of cathodoluminescent intensity with experimental characteristics. The obtained parameters are very sensitive to additional treatments of phosphor surface, especially to chemical modification by even small amounts of inorganic oxides. The proposed method offers a simple and rapid way of controlling recombination parameters of luminescent materials. © 2002 American Institute of Physics.
Show PACS
78.60.Hk Cathodoluminescence, ionoluminescence
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.25.+i Surface conductivity and carrier phenomena

Light-induced assembly of tailored droplet arrays in nematic emulsions

Takahiro Yamamoto, Jun Yamamoto, Bohdan I. Lev, and Hiroshi Yokoyama

Appl. Phys. Lett. 81, 2187 (2002); http://dx.doi.org/10.1063/1.1508816 (3 pages) | Cited 17 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Dynamic manipulation of droplets could be achieved by light in a nematic liquid crystal (LC) doped with photochromic azobenzene derivatives. On irradiation of ultraviolet light, the trans→cis photoisomerization drives a directional motion of the droplets towards the cis-rich region and assembled close-packed two-dimensional hexagonal colloidal crystals. This behavior is mainly attributable to the reduction of the droplet-LC interfacial tension, associated with the enhanced surface activity of cis isomers. We also performed photochemical assembly of tailored droplet arrays by projection of computer-generated images on the samples. The photoinduced manipulation of droplets will provide a versatile approach to microstructuring of LC devices. © 2002 American Institute of Physics.
Show PACS
82.70.Kj Emulsions and suspensions
82.30.Qt Isomerization and rearrangement
82.50.-m Photochemistry
83.80.Xz Liquid crystals: nematic, cholesteric, smectic, discotic, etc.
42.70.Df Liquid crystals
61.30.-v Liquid crystals

High-quality SiO2 film formation by highly concentrated ozone gas at below 600 °C

Tetsuya Nishiguchi, Hidehiko Nonaka, Shingo Ichimura, Yoshiki Morikawa, Mitsuru Kekura, and Masaharu Miyamoto

Appl. Phys. Lett. 81, 2190 (2002); http://dx.doi.org/10.1063/1.1507829 (3 pages) | Cited 22 times

Online Publication Date: 9 September 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Highly concentrated (>93 vol %) ozone (O3) gas was used to oxidize silicon for obtaining high-quality SiO2 film at low temperature. Compared to O2 oxidation, more than 500 °C lower temperature oxidation (i.e., from 830 to 330 °C) has been enabled for achieving the same SiO2 growth rate. A 6 nm SiO2 film, for example, could be grown at 600 °C within 3 min at 900 Pa O3 atmosphere. The temperature dependence of the oxidation rate is relatively low, giving an activation energy for the parabolic rate constant of 0.32 eV. Furthermore, a 400 °C grown SiO2 film was found to have satisfactory electrical properties with a small interface trap density (5×1010 cm−2/eV) and large breakdown field (14 MV/cm). © 2002 American Institute of Physics.
Show PACS
81.65.Mq Oxidation
73.61.Ng Insulators
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close