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 Jan 1999

Volume 74, Issue 3, pp. 329-478

Return to All Sections
back to top
RSS Feeds

Magnetic and transport properties of III–V based magnetic semiconductor (GaMn)As: Growth condition dependence

Hiromasa Shimizu, Toshiaki Hayashi, Tatau Nishinaga, and Masaaki Tanaka

Appl. Phys. Lett. 74, 398 (1999); http://dx.doi.org/10.1063/1.123082 (3 pages) | Cited 63 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied growth condition dependence of magnetic and transport properties of magnetic semiconductor (GaMn)As grown by low-temperature molecular-beam epitaxy (LT-MBE). With increasing substrate temperature and decreasing As overpressure during the growth of (Ga1−xMnx)As with x=0.043, the hole concentration increased, the conduction behavior changed from semiconducting to metallic, and the ferromagnetic transition temperature became higher. This is explained by a decrease in the compensation of Mn acceptors by the reduction of excess As related defects in the LT-MBE grown (GaMn)As. Our experimental results indicate that the selection of the MBE growth parameters is very important for better controlling the electronic and magnetic properties of (GaMn)As. © 1999 American Institute of Physics.
Show PACS
75.50.Pp Magnetic semiconductors
73.61.Ey III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
75.70.Ak Magnetic properties of monolayers and thin films
71.55.Eq III-V semiconductors
81.05.Ea III-V semiconductors
68.55.-a Thin film structure and morphology
75.50.Dd Nonmetallic ferromagnetic materials
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
72.60.+g Mixed conductivity and conductivity transitions
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)

Intraband absorption in Ge/Si self-assembled quantum dots

P. Boucaud, V. Le Thanh, S. Sauvage, D. Débarre, and D. Bouchier

Appl. Phys. Lett. 74, 401 (1999); http://dx.doi.org/10.1063/1.123083 (3 pages) | Cited 40 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have observed intraband absorption in Ge/Si self-assembled quantum dots. The self-assembled quantum dots are grown at 550 °C by chemical vapor deposition. Atomic force microscopy shows that the quantum dots have a square-based pyramidal shape (≈100 nm base length) and a density  ≈ 2×109 cm−2. Intraband absorption in the valence band is observed around 300 meV (4.2 μm wavelength) using a photoinduced spectroscopy technique. The intraband absorption is in-plane polarized. It is attributed to bound-to-continuum transitions since the intraband energy corresponds to the energy difference between the Si band gap and the photoluminescence energy of the quantum dots. The magnitude of the intraband absorption saturates when the ground level of the quantum dots is filled. This feature allows the measurement of the in-plane absorption cross section of the intraband transition which is found as large as 2×10−13 cm2. © 1999 American Institute of Physics.
Show PACS
78.66.Db Elemental semiconductors and insulators
78.30.Am Elemental semiconductors and insulators
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.05.Cy Elemental semiconductors

Stripe-width dependence of threshold current for gain-guided AlGaInN laser diodes

D. P. Bour, M. Kneissl, L. T. Romano, R. M. Donaldson, C. J. Dunnrowicz, N. M. Johnson, and G. A. Evans

Appl. Phys. Lett. 74, 404 (1999); http://dx.doi.org/10.1063/1.123084 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The threshold current density of narrow-stripe gain-guided nitride laser diodes increases very rapidly as the stripe width is made narrow. To examine this behavior, waveguide simulations, incorporating the complex refractive indices associated with optical gain, have been used to analyze the lateral optical modes of gain-guided laser diodes. Threshold current was then determined from the gain–current relationship of our laser material, which was obtained experimentally. These evaluations reveal that gain guiding, coupled with a carrier-induced index depression, offer a reasonable explanation for the rapid increase in threshold when the stripe width becomes less than 5 μm. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
78.66.Fd III-V semiconductors
42.79.Gn Optical waveguides and couplers

Proton bombardment-induced electron traps in epitaxially grown n-GaN

F. D. Auret, S. A. Goodman, F. K. Koschnick, J.-M. Spaeth, B. Beaumont, and P. Gibart

Appl. Phys. Lett. 74, 407 (1999); http://dx.doi.org/10.1063/1.123043 (3 pages) | Cited 45 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using deep-level transient spectroscopy, we have studied the electrical properties of defects introduced in epitaxially grown n-GaN during 2-MeV proton bombardment. The main defects detected, ER2 and ER3, are introduced at rates of 400±150 and 600±100 cm−1, respectively, and have energy levels at 0.16±0.03 and 0.20±0.01 eV, respectively, below the conduction band. A less prominent defect, ER1, with an energy level at 0.13±0.01 eV below the conduction band, is introduced at a rate of 30±10 cm−1. The small capture cross section of ER3 [(8±4)×10−18 cm2] implies that it is in a neutral or negative state when above the Fermi level. © 1999 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
73.61.Ey III-V semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
61.80.Jh Ion radiation effects
61.82.Fk Semiconductors

Band gaps and band offsets in strained GaAs1−ySby on InP grown by metalorganic chemical vapor deposition

M. Peter, N. Herres, F. Fuchs, K. Winkler, K.-H. Bachem, and J. Wagner

Appl. Phys. Lett. 74, 410 (1999); http://dx.doi.org/10.1063/1.123044 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metastable GaAs1−ySby with 0.22<y<0.70 has been grown pseudomorphically strained on (001) InP substrates using metalorganic chemical vapor deposition. The Sb concentration and layer thicknesses, ranging from 24 to 136 nm, were determined by high resolution x-ray diffraction (HRXRD) measurements. Low-temperature photoluminescence (PL) spectroscopy revealed spatially indirect band-to-band emission of electrons localized in the InP and holes in the GaAs1−ySby. At increased excitation power densities samples with layer thicknesses above 65 nm showed, also, spatially direct PL across the band gap of the strained GaAs1−ySby. From the PL data the band gap energy and the band offsets of GaAs1–ySby relative to InP were derived and compared with the predictions of the Model Solid Theory. © 1999 American Institute of Physics.
Show PACS
71.20.Nr Semiconductor compounds
81.05.Ea III-V semiconductors
68.55.-a Thin film structure and morphology
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Strong normal-incidence infrared absorption in self-organized InAs/InAlAs quantum dots grown on InP(001)

A. Weber, O. Gauthier-Lafaye, F. H. Julien, J. Brault, M. Gendry, Y. Désieres, and T. Benyattou

Appl. Phys. Lett. 74, 413 (1999); http://dx.doi.org/10.1063/1.123045 (3 pages) | Cited 44 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
InAs self-assembled quantum dots in InAlAs matrix grown on InP(001) substrates have been fabricated using Stranski–Krastanov growth mode. A strong in-plane polarized intraband absorption in the 10.6–20 μm wavelength region has been observed and ascribed to a transition from the ground electron state to an excited state confined in the layer plane along the [110] direction. The absorption at normal-incidence reaches 7.8% for ten layers of n-doped quantum dots. The oscillator strength of the intraband transition is comparable to that achieved in quantum wells for a conduction band intersubband transition. The dependence of the intraband absorption on carrier concentration and temperature suggests a quantum-wire type confinement potential. © 1999 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.30.Fs III-V and II-VI semiconductors
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Molecular doping of gallium nitride

J. I. Pankove, J. T. Torvik, C.-H. Qiu, I. Grzegory, S. Porowski, P. Quigley, and B. Martin

Appl. Phys. Lett. 74, 416 (1999); http://dx.doi.org/10.1063/1.123046 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoconductivity experiments were made on bulk GaN doped with Mg and O and grown using high pressures and high temperature. The bulk GaN:Mg,O was insulating, indicating compensation. The photoconductive response to photons above the energy band gap was comparable to that of epitaxially grown GaN:Mg samples. However, the UV-to-visible rejection ratio (solar blindness) was three orders of magnitude larger in the bulk GaN:Mg,O than for other epitaxially grown GaN samples. The dramatically improved visible rejection ratio is tentatively attributed to molecular doping by paired donors (O) and acceptors (Mg). Vacuum UV reflectance was performed to verify if MgO critical point transitions could be found in the GaN:Mg,O. A reflectance peak at 6.7 eV was found in both MgO and GaN:Mg,O. © 1999 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
71.55.Eq III-V semiconductors
78.66.Fd III-V semiconductors
73.50.Pz Photoconduction and photovoltaic effects
61.72.uj III-V and II-VI semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
85.40.Ry Impurity doping, diffusion and ion implantation technology
78.40.Fy Semiconductors
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close