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

24 Jul 1995

Volume 67, Issue 4, pp. 449-574

Page 2 of 2 Pages Previous Page | Jump to Page

Enhancement of radiative recombination in Si‐based quantum wells with neighboring confinement structure

N. Usami, F. Issiki, D. K. Nayak, Y. Shiraki, and S. Fukatsu

Appl. Phys. Lett. 67, 524 (1995); http://dx.doi.org/10.1063/1.115176 (3 pages) | Cited 24 times

Full Text: | Download PDF

Show Abstract
Intense photoluminescence (PL) was observed from a new class of Si‐based quantum well structures (QWs), that is, neighboring confinement structure (NCS). NCS consists of a single pair of tensile‐strained‐Si layer and a compressive‐strained Si1−yGey layer sandwiched by completely relaxed Si1−xGex ( layers. In spite of the indirect band structure in real and k spaces, radiative recombination was enhanced compared with not only type‐II strained‐Si/relaxed‐Si1−xGex QWs but also type‐I strained‐Si1−yGey/relaxed‐Si1−xGex QWs. PL without phonon participation was found to dominate the spectrum possibly due to the effective carrier confinement for both electrons and holes. Quantum confinement effect was clearly observed by varying the well width, showing that the expected band alignment is realized. © 1995 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.55.Hx Other solid inorganic materials

Indium phosphide passivation using thin layers of cadmium sulfide

K. Vaccaro, H. M. Dauplaise, A. Davis, S. M. Spaziani, and J. P. Lorenzo

Appl. Phys. Lett. 67, 527 (1995); http://dx.doi.org/10.1063/1.115177 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
The electrical properties of the silicon dioxide/n‐type (100) InP interface were significantly improved by thin interlayers of chemical bath deposited CdS. The CdS layer and CdS/InP interface were investigated with x‐ray photoelectron spectroscopy (XPS) and photoluminescence (PL). XPS data showed reduction of native oxides and the prevention of subsequent substrate oxide growth following CdS layer deposition. PL spectra, measured between 1.0 and 1.3 μm, indicate a reduction in phosphorus vacancies. Metal–insulator–semiconductor (MIS) capacitors fabricated with CdS‐treated InP substrates displayed interface‐state densities below 1×1011 eV−1 cm−2 when determined from the difference between the high‐ and low‐frequency capacitance data.
Show PACS
81.65.-b Surface treatments
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.20.At Surface states, band structure, electron density of states

Interface state buildup by high‐field stressing in various metal‐oxide‐semiconductor insulators using deep level transient spectroscopy

S. Belkouch, C. Jean, C. Aktik, and E. L. Ameziane

Appl. Phys. Lett. 67, 530 (1995); http://dx.doi.org/10.1063/1.115178 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
The buildup of interface states with high field (HF) stressing have been observed in thermally grown oxide, N2O nitrided oxide (NO), and reoxided nitrided oxide (RNO). The DLTS technique was used to analyze the electronic properties of the Si/SiO2 interface. We show that N2O nitridation of SiO2 changes the electronic distribution of states at the Si/SiO2 interface after HF electrical stress. Our results indicate that this nitrogen plays an important role in preventing the creation of a center at Et1=0.34 eV below the bottom of the conduction band. However, the nitrogen is responsible for a new level at Et2=0.22 eV below the bottom of the conduction band after the NO device is stressed. Also, reoxidation and increasing time of the reoxidation shift the maximum of the peak level away from the Et2 toward Et1. © 1995 American Institute of Physics.
Show PACS
73.20.Hb Impurity and defect levels; energy states of adsorbed species
72.20.Ht High-field and nonlinear effects
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Spontaneous and stimulated emission from photopumped GaN grown on SiC

A. S. Zubrilov, V. I. Nikolaev, D. V. Tsvetkov, V. A. Dmitriev, K. G. Irvine, J. A. Edmond, and C. H. Carter

Appl. Phys. Lett. 67, 533 (1995); http://dx.doi.org/10.1063/1.115179 (3 pages) | Cited 45 times

Full Text: | Download PDF

Show Abstract
Photoluminescence of GaN layers grown on 6H–SiC substrates was studied in the temperature range 77–900 K. GaN layers were grown by metalorganic chemical vapor deposition. The temperature dependence of the band gap of GaN was measured throughout the entire temperature range. Edge cavity stimulated emission from photopumped GaN layers was observed in the temperature range 77–450 K. The full width at half‐maximum (FWHM) of the stimulated emission peak was ∼3 nm at 300 K and ∼7 nm at 450 K. Multipass stimulated emission with Fabry–Pérot modes was detected from GaN. The FWHM of Fabry–Pérot modes was ∼0.2 nm (300 K). © 1995 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
78.45.+h Stimulated emission

Magneto‐optical absorption spectra and self‐similarity of GaAs–(Ga,Al)As quasiperiodic Fibonacci superlattices under in‐plane magnetic fields

A. Bruno‐Alfonso, L. E. Oliveira, and M. de Dios‐Leyva

Appl. Phys. Lett. 67, 536 (1995); http://dx.doi.org/10.1063/1.115180 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
A theoretical study of the effects of in‐plane magnetic fields on the interband optical absorption spectra of quasiperiodic GaAs–(Ga,Al)As Fibonacci superlattices is presented within the effective‐mass approximation. The electron‐envelope wave functions and magnetic subbands are obtained by an expansion in harmonic‐oscillator wave functions. The theoretical optical absorption spectra are calculated for magnetic fields related by integer powers of the golden mean τ=(1+√5)/2. It is unambiguously shown that, for magnetic‐field values scaled by τ2n, the corresponding optical absorption spectra essentially exhibit a self‐similar behavior, with the width of the peaks increasing linearly with the field, in agreement with the experimental results by D. Toet, M. Potemski, Y. Y. Wang, J. C. Maan, L. Tapter, and K. Ploog [Phys. Rev. Lett. 66, 2128 (1991)]. © 1995 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors
78.20.Ls Magneto-optical effects

Lattice dilation by free electrons in heavily doped GaAs:Si

M. Leszczynski, J. Bak‐Misiuk, J. Domagala, J. Muszalski, M. Kaniewska, and J. Marczewski

Appl. Phys. Lett. 67, 539 (1995); http://dx.doi.org/10.1063/1.115181 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Lattice constants of GaAs layers grown by molecular beam epitaxy were examined by using the high resolution x‐ray diffractometer. For highly doped samples (up to 9×1018 cm−3 of free‐electron concentration) we observed an increase of the lattice constant with respect to the undoped layers. Since substitutional silicon atoms decrease the lattice constant of GaAs, the results are explained by the influence of free‐electrons via the deformation potential of the Γ minimum of the conduction band. The best fit to our diffractometric data was obtained for the band‐gap deformation potential equal to −8.5 eV. © 1995 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
61.72.uj III-V and II-VI semiconductors
61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.

Thermal and plasma‐assisted nitridation of GaAs(100) using NH3

M. E. Jones, J. R. Shealy, and J. R. Engstrom

Appl. Phys. Lett. 67, 542 (1995); http://dx.doi.org/10.1063/1.115182 (3 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
The thermal and plasma‐assisted nitridation of GaAs(100) using NH3 has been examined employing x‐ray diffraction, Auger electron spectroscopy, and atomic force microscopy to characterize the nitrided films. All thermally nitrided films were composed of a mixture of hexagonal and cubic GaN, whereas the addition of plasma excitation produced films purely of the cubic structure. Thicknesses of the thermally nitrided films, up to 7000 Å, increased with both increasing temperature and nitridation time. The plasma‐assisted process holds promise for the formation of templates for homoepitaxial growth of cubic GaN. © 1995 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.65.-b Surface treatments

Effect of silver in Bi1.7Pb0.3Sr2−xAgxCa2Cu3Oy

Y. Yu, X. Jin, S. Y. Ding, Z. Y. Zhen, X. X. Yao, and G. J. Shen

Appl. Phys. Lett. 67, 545 (1995); http://dx.doi.org/10.1063/1.115183 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
The oxide superconductor Bi1.7Pb0.3Sr2−xAgxCa2Cu3Oy has been synthesized under the ordinary pressure. The x‐ray diffraction spectra of these specimens show the presence of only 2212 phase when x<0.4, and the transition temperature achieved 99 K. With the x increase, the structure of sample transfers to 2223 phase. The investigation indicates that substitution of Sr2+ by Ag1+ increases the distance between layers. This may respond to Tc increase in 2212 phase and 2223 phase form at a relatively low temperature. © 1995 American Institute of Physics.
Show PACS
74.72.-h Cuprate superconductors
74.62.Dh Effects of crystal defects, doping and substitution

Nitridation of GaAs surfaces using nitrogen through a hot tungsten filament

Toshiki Makimoto and Naoki Kobayashi

Appl. Phys. Lett. 67, 548 (1995); http://dx.doi.org/10.1063/1.115184 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
This letter reports the nitridation of GaAs surfaces using N2 through a hot tungsten filament. After nitridation, GaAs cap layers were grown by molecular beam epitaxy to form GaAs/GaN/GaAs structures. For these structures, we determine the sheet nitrogen atom concentration by secondary ion mass spectrometry analysis. The sheet nitrogen atom concentration is proportional to the square root of the N2 pressure, indicating that N2 molecules are decomposed into nitrogen atoms to adsorb on the GaAs surfaces. The activation energy of this decomposition process is 3.6±0.4 eV. © 1995 American Institute of Physics.
Show PACS
81.65.-b Surface treatments
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Vortex dynamics at microwave frequencies in patterned YBa2Cu3O7−δ thin films

Balam A. Willemsen, S. Sridhar, John S. Derov, and José H. Silva

Appl. Phys. Lett. 67, 551 (1995); http://dx.doi.org/10.1063/1.115166 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
YBa2Cu3O7−δ thin films patterned in the form of a meander line resonant structure, are used as a sensitive probe of vortex dynamics at microwave frequencies. The experiments enable highly sensitive measurements of the complex microwave surface impedance Zs(ω,T,H) of YBa2Cu3O7−δ as a function of applied dc magnetic field, temperature, and frequency. The Zs(H,T) versus H data yield direct experimental results for the vortex viscosity and pinning force constant, which are compared with microscopic theory. © 1995 American Institute of Physics.
Show PACS
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.72.-h Cuprate superconductors
74.25.N- Response to electromagnetic fields

Formation of YBa2Cu3O7−y/BaTiO3 multistructures by pulsed laser deposition for high‐temperature superconducting device applications

S. Hontsu, J. Ishii, H. Tabata, and T. Kawai

Appl. Phys. Lett. 67, 554 (1995); http://dx.doi.org/10.1063/1.115167 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
The formation of YBa2Cu3O7−y(YBCO)/BaTiO3(BTO)//SrTiO3(STO) (100) and BTO/ YBCO//STO(100) bilayer structures is demonstrated for the construction of a superconductor ferroelectric field transistor. The resulting films of the bilayers have highly c‐axis oriented structure. Epitaxial YBCO films formed on the BTO//STO(100) have a zero resistance temperature of 88.9 K. The surface morphology of the epitaxial BTO films on the YBCO//STO is very smooth with a mean surface roughness of 32 Å. Moreover, the Au/BTO/YBCO structures have been fabricated, and the dielectric constant and remanent polarization of BTO layer are obtained to be 180 and 3.5 μC/cm2 at 77 K, respectively. © 1995 American Institute of Physics.
Show PACS
85.25.Qc Superconducting surface acoustic wave devices and other superconducting devices
81.15.Fg Pulsed laser ablation deposition
74.78.-w Superconducting films and low-dimensional structures

Thickness dependence of magnetoresistance in La–Ca–Mn–O epitaxial films

S. Jin, T. H. Tiefel, M. McCormack, H. M. O’Bryan, L. H. Chen, R. Ramesh, and D. Schurig

Appl. Phys. Lett. 67, 557 (1995); http://dx.doi.org/10.1063/1.115168 (3 pages) | Cited 117 times

Full Text: | Download PDF

Show Abstract
Colossal magnetoresistance in excess of 106% has been obtained (at 110 K, H=6 T) in epitaxially grown La–Ca–Mn–O thin films. The as‐deposited film exhibits a substantial magnetoresistance value of 39 000%, which is further improved by heat treatment. The magnetoresistance is found to be strongly dependent on film thickness, with the value reaching the maxima at ∼1000 Å thickness, and then reduced by orders of magnitude when the film is made thicker than ∼2000 Å. This behavior is interpreted in terms of lattice strain in the La–Ca–Mn–O films. © 1995 American Institute of Physics.
Show PACS
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.-r Electrical properties of specific thin films

The road to Fe16N2 formation in N+ implanted 57Fe enriched films

E. Leroy, C. Djega‐Mariadassou, H. Bernas, O. Kaitasov, R. Krishnan, and M. Tessier

Appl. Phys. Lett. 67, 560 (1995); http://dx.doi.org/10.1063/1.115169 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
20 keV N+ ions have been implanted on 57Fe enriched Fe films and RF deposited on glass and NaCl substrates with various fluences up to 3.0×1016 N+/cm2. Conversion electron Mossbauer spectroscopy and transmission electron microscopy measurements performed at room temperature on the as‐implanted samples reveal the presence of α‐Fe, α′‐martensite, and ϵ‐Fe3−xN phases. α″‐Fe16N2 is only detected after a subsequent annealing at 220 °C; α′‐martensite with a low nitrogen content appears as the precursor of α″, The additional nitrogen content needed for this process is supplied by the ϵ phase. © 1995 American Institute of Physics.
Show PACS
64.70.K- Solid-solid transitions
81.10.Aj Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
61.80.Jh Ion radiation effects

Nanostructured Nd–Fe–B magnets with enhanced remanence

J. Wecker, K. Schnitzke, H. Cerva, and W. Grogger

Appl. Phys. Lett. 67, 563 (1995); http://dx.doi.org/10.1063/1.115170 (3 pages) | Cited 28 times

Full Text: | Download PDF

Show Abstract
Nanostructured isotropic Nd–Fe–B magnets with enhanced remanence were produced by hot compaction of mechanically alloyed Nd–Fe–B powders at temperatures of about 600 °C. Phase formation occurred during hot pressing without significant grain growth. The microstructure is a two phase nanocomposite of hard magnetic Nd2Fe14B and soft magnetic α‐Fe with an average grain size of about 20 nm. These small dimensions allow effective exchange interactions between hard and soft magnetic grains and result in an enhancement of the remanence by more than 30% above the Stoner–Wolfarth limit expected for noninteracting single domain particles. So far, the best results are a remanence of 1.0 T, an energy density of 121 kJ/m3, and a coercivity of 4.2 kA/cm for a Nd–Fe–Co–Si–B magnet. © 1995 American Institute of Physics.
Show PACS
75.50.Vv High coercivity materials
81.20.Ev Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
81.40.Rs Electrical and magnetic properties related to treatment conditions

Normal‐incidence strained‐layer superlattice Ge0.5Si0.5/Si photodiodes near 1.3 μm

F. Y. Huang, X. Zhu, M. O. Tanner, and K. L. Wang

Appl. Phys. Lett. 67, 566 (1995); http://dx.doi.org/10.1063/1.115171 (3 pages) | Cited 32 times

Full Text: | Download PDF

Show Abstract
Ge0.5Si0.5 strained‐layer pin photodiodes, in which multiple strained layers serve as the absorption region, have been fabricated. These devices exhibit an optical response at wavelengths beyond 1.3 μm at normal incidence. The measured external quantum efficiencies at an applied bias of 4 V are 17% at 0.85 μm and 1% at 1.3 μm, respectively. Excellent electrical characteristics evidenced by the avalanche breakdown at 20 V have also been demonstrated. © 1995 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
78.66.Li Other semiconductors
73.50.Pz Photoconduction and photovoltaic effects

A new concept for the design and realization of metal based single electron devices: Step edge cut‐off

S. Altmeyer, B. Spangenberg, and H. Kurz

Appl. Phys. Lett. 67, 569 (1995); http://dx.doi.org/10.1063/1.115172 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
To increase the operating temperature of a single electron circuit, it is necessary to reduce the capacitance of the tunnel junction. Usually this is done by reducing the linewidth of the capacitor forming metal stripes, which are sandwiched with an intermediate insulator. The use of alternative materials, however, allows capacitance reduction by means of thicker isolation layers or by a capacitor geometry different from a sandwich. The new SECO (step edge cut off) method, for the fabrication of single electron devices will be presented. © 1995 American Institute of Physics.
Show PACS
73.40.Gk Tunneling
85.30.De Semiconductor-device characterization, design, and modeling

Pulsed laser ablation synthesis and characterization of layered Pt/SrBi2Ta2O9/Pt ferroelectric capacitors with practically no polarization fatigue

R. Dat, J. K. Lee, O. Auciello, and A. I. Kingon

Appl. Phys. Lett. 67, 572 (1995); http://dx.doi.org/10.1063/1.115173 (3 pages) | Cited 146 times

Full Text: | Download PDF

Show Abstract
Pulsed laser ablation deposition was used to synthesize polycrystalline SrBi2Ta2O9 layered ferroelectric thin films on platinized silicon substrates. Top electrodes were produced by dc magnetron sputter deposition to fabricate capacitors for electrical tests. The polarization electric field hysteresis loops showed saturation in the 2–4 V range with a coercive field of 25 kV/cm. The capacitors showed practically no polarization fatigue up to 1011 switching cycles. The resistivity of the SrBi2Ta2O9 for a coercive field of 100 kV/cm was approximately 2×1011 Ω cm. Retention and imprint characteristics of these capacitors showed no degradation as a function of cumulative waiting times. © 1995 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
77.80.-e Ferroelectricity and antiferroelectricity
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close