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

6 Sep 1999

Volume 75, Issue 10, pp. 1345-1481

Page 1 of 2 Pages Next Page | Jump to Page
back to top
RSS Feeds

GaAs/AlGaAs superlattice quantum cascade lasers at λ ≈ 13 μm

G. Strasser, S. Gianordoli, L. Hvozdara, W. Schrenk, K. Unterrainer, and E. Gornik

Appl. Phys. Lett. 75, 1345 (1999); http://dx.doi.org/10.1063/1.124688 (3 pages) | Cited 35 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the realization of an injection laser based on intraband transitions in a finite AlGaAs/GaAs superlattice. The active material is a 30 period sequence of injectors/active regions made from AlGaAs/GaAs quantum wells. By an applied electric field, electrons are injected into the second miniband of a chirped superlattice and relax radiative to the lowest miniband. At a heat-sink temperature of 10 K, the laser emission wavelength is 12.9 μm with peak optical powers exceeding 100 mW and a threshold current density of 9.8 kA/cm2. The maximum operating temperature is 50 K. For this device, a waveguide consisting of heavily doped GaAs cladding and low doped core layers has been used as a plasma-enhanced confinement. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Nonlinearly induced escape from a defect state in waveguide arrays

U. Peschel, R. Morandotti, J. S. Aitchison, H. S. Eisenberg, and Y. Silberberg

Appl. Phys. Lett. 75, 1348 (1999); http://dx.doi.org/10.1063/1.124689 (3 pages) | Cited 40 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We experimentally investigate the linear and nonlinear optical properties of a nonuniform waveguide array. By reducing the width of a single waveguide, we decrease its effective index and induce waveguiding along the defect. Due to the positive nonlinearity, the index difference is reduced for increasing power levels with the result that the field escapes. Waveguiding is suppressed by the action of the nonlinearity. © 1999 American Institute of Physics.
Show PACS
42.65.Wi Nonlinear waveguides
42.82.Et Waveguides, couplers, and arrays
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
71.55.Eq III-V semiconductors
78.66.Fd III-V semiconductors

Wavelength-dependent optical degradation of green II–VI laser diodes

R. Vogelgesang, J. J. Liang, V. Wagner, H. J. Lugauer, J. Geurts, A. Waag, and G. Landwehr

Appl. Phys. Lett. 75, 1351 (1999); http://dx.doi.org/10.1063/1.124690 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter we report on optical degradation studies on BeMgZnSe separate confinement quantum well laser structures for the blue-green spectral region. The wavelength of the incident light has been tuned from 3.81 down to 2.10 eV, corresponding to an energy range from above the band gap of the cladding layers down to below the band gap of the quantum well. The dominant degradation mechanism is initiated when electron hole pairs are created in the quantum well. Absorption of light in deep defect bands, e.g., of the p-type cladding material is negligible in these structures. The strain state of the quantum well is one possible driving force for the degradation. In this context, point defect propagation as well as a structural phase transition of the ZnCdSe quantum well are discussed. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
78.66.Hf II-VI 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
78.55.Et II-VI semiconductors
71.55.Gs II-VI semiconductors

Piezoelectric effects on many-body optical gain of zinc-blende and wurtzite GaN/AlGaN quantum-well lasers

Seoung-Hwan Park, Shun-Lien Chuang, and Doyeol Ahn

Appl. Phys. Lett. 75, 1354 (1999); http://dx.doi.org/10.1063/1.124691 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electronic and optical properties for (001)-, (111)-oriented zinc-blende (ZB), and (0001)-oriented wurtzite (WZ) structures are investigated taking into account the piezoelectric (PZ) effects. Self-consistent (SC) calculation of electronic structure is also considered within Hartree approximation. Using the SC model with the PZ field, we show that the many-body optical gain of (111)-oriented ZB and (0001)-oriented WZ quantum well (QW) lasers is reduced compared to results using the flat-band (FB) model. This is caused by the separation between the electron and hole wave functions in the presence of PZ electric field. However, when the optical gain is plotted as a function of the radiative current density Jrad, it is found that there is no significant difference between the results of the FB and SC models. We believe that this is due to the fact that the peak gain and the radiative recombination current are reduced simultaneously with increasing PZ field. For the same threshold gain level, the ZB and WZ quantum well structures are expected to have nearly the same threshold current density Jth within 10%. © 1999 American Institute of Physics.
Show PACS
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Px Semiconductor lasers; laser diodes
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
77.65.Ly Strain-induced piezoelectric fields
78.66.Fd III-V semiconductors

Photoemission study of the interface between phenyl diamine and treated indium–tin–oxide

Quoc Toan Le, F. Nüesch, L. J. Rothberg, E. W. Forsythe, and Yongli Gao

Appl. Phys. Lett. 75, 1357 (1999); http://dx.doi.org/10.1063/1.124692 (3 pages) | Cited 35 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The interface formation between indium–tin–oxide (ITO) having various work functions and N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) was investigated using x-ray and ultraviolet photoelectron spectroscopy. Phosphoric acid and tetrabutylammonium hydroxide were used to modify the ITO work function. The energy difference between the highest occupied molecular orbital (HOMO) position of NPB and the ITO Fermi level can be varied substantially by surface treatment. The work function of acid-treated ITO dramatically decreases after deposition of a thin NPB layer. We attribute this to the reaction between the NPB nitrogen and the proton of the adsorbed dipole layer. No significant reaction was observed for NPB deposited on standard ITO. © 1999 American Institute of Physics.
Show PACS
79.60.Jv Interfaces; heterostructures; nanostructures
73.30.+y Surface double layers, Schottky barriers, and work functions
81.65.-b Surface treatments
73.20.At Surface states, band structure, electron density of states

Fabrication of thin-film InGaN light-emitting diode membranes by laser lift-off

W. S. Wong, T. Sands, N. W. Cheung, M. Kneissl, D. P. Bour, P. Mei, L. T. Romano, and N. M. Johnson

Appl. Phys. Lett. 75, 1360 (1999); http://dx.doi.org/10.1063/1.124693 (3 pages) | Cited 93 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Indium–gallium nitride (InGaN) multiple-quantum-well (MQW) light-emitting diode (LED) membranes, prefabricated on sapphire growth substrates, were created using pulsed-excimer laser processing. The thin-film InGaN MQW LED structures, grown on sapphire substrates, were first bonded onto a Si support substrate with an ethyl cyanoacrylate-based adhesive. A single 600 mJ/cm2, 38 ns KrF (248 nm) excimer laser pulse was directed through the transparent sapphire, followed by a low-temperature heat treatment to remove the substrate. Free-standing InGaN LED membranes were then fabricated by immersing the InGaN LED/adhesive/Si structure in acetone to release the device from the supporting Si substrate. The current–voltage characteristics and room-temperature emission spectrum of the LEDs before and after laser lift-off were unchanged. © 1999 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
85.60.Bt Optoelectronic device characterization, design, and modeling
42.62.-b Laser applications
78.66.Fd III-V semiconductors
78.60.Fi Electroluminescence

Short-coherence photorefractive holography in multiple-quantum-well devices using light-emitting diodes

M. Tziraki, R. Jones, P. M. W. French, D. D. Nolte, and M. R. Melloch

Appl. Phys. Lett. 75, 1363 (1999); http://dx.doi.org/10.1063/1.124694 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate an application of light-emitting diodes to photorefractive holography with multiple-quantum-well devices. Holograms corresponding to three-dimensional images with a depth resolution of less than 10 μm were recorded, with image acquisition times as short as 5 ms. © 1999 American Institute of Physics.
Show PACS
42.40.Ht Hologram recording and readout methods
42.70.Ln Holographic recording materials; optical storage media
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
85.60.Jb Light-emitting devices
78.66.Fd III-V semiconductors

Ultrafast low-temperature grown AlGaAs/GaAs photorefractive quantum wells using point defects as capture centers

M. H. Zhang, Q. Huang, Y. F. Zhang, J. M. Zhou, Q. Li, and Z. Y. Xu

Appl. Phys. Lett. 75, 1366 (1999); http://dx.doi.org/10.1063/1.124695 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
At a medium substrate temperature of 400 °C and a lower As flux, we have grown an ultrafast AlGaAs/GaAs photorefractive multiple quantum well (MQW) structure by molecular beam epitaxy. The as-grown sample exhibits strong photorefractive effect under the transverse Frantz–Keldysh geometry. A peak electroabsorption of 2100 cm−1 is measured in the as-grown sample in an 11 kV/cm dc electric field, and the peak photorefractive diffraction efficiency can be 1.2%. After postgrowth annealing, the photorefractive effect becomes weak and disappears in samples annealed above 700 °C. Using optical transient current spectroscopy, deep levels are measured in these samples. It is found that deep levels are stable against annealing until 700 °C. Using a pump-probe technique, carrier lifetimes are measured at room temperature. We find that the as-grown sample has a lifetime of 20 ps, while the 700 °C annealed sample has a lifetime of more than 200 ps. The ultrafast lifetime in the as-grown sample is caused by point defects, not by As clusters. Our result show that AlGaAs/GaAs MQW structure grown around 400 °C has better performance of the photorefractive effect. © 1999 American Institute of Physics.
Show PACS
42.70.Ln Holographic recording materials; optical storage media
78.47.-p Spectroscopy of solid state dynamics
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
78.66.Fd III-V semiconductors
71.55.Eq III-V semiconductors
73.61.Ey III-V semiconductors
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.20.Jq Electro-optical effects
61.72.Cc Kinetics of defect formation and annealing
61.72.J- Point defects and defect clusters
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Radio frequency discharge excited diffusively cooled kilowatt carbon monoxide slab waveguide laser with a three mirror resonator

Jianguo Xin, Wang Zhang, and Wentao Jiao

Appl. Phys. Lett. 75, 1369 (1999); http://dx.doi.org/10.1063/1.124696 (2 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we describe a kilowatt radio frequency discharge excited diffusively cooled slab waveguide carbon monoxide laser, in which the top and bottom electrodes were cooled with liquid nitrogen and which utilized a modified resonator. With this design we obtained a maximum laser power output of 1020 W, which was 10% higher than the same device employing a conventional unstable resonator. © 1999 American Institute of Physics.
Show PACS
42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Fabrication of a substrate-independent aluminum oxide-GaAs distributed Bragg reflector

D. E. Wohlert, H. C. Lin, K. L. Chang, G. W. Pickrell, J. H. Epple, K. C. Hsieh, and K. Y. Cheng

Appl. Phys. Lett. 75, 1371 (1999); http://dx.doi.org/10.1063/1.124697 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a method for forming a top distributed Bragg reflector (DBR) during very-low temperature (VLT) molecular-beam epitaxy (MBE) growth that is independent of the substrate being used. By varying the arsenic overpressure during VLT MBE, it was determined by Auger electron spectroscopy and cross-section transmission electron microscopy that alternating layers of polycrystalline GaAs and amorphous (Al,As) can be deposited. Because these layers are not single crystal, they can be grown on any host lattice. After lateral wet oxidation, the polycrystalline GaAs does not undergo any significant changes; whereas the amorphous (Al,As) becomes an amorphous aluminum oxide. An index step of Δn = 1.88 is realized between these two layers which makes it possible to fabricate a high efficiency DBR with very few polycrystal-GaAs/amorphous-Al-oxide pairs on GaAs-, GaP-, or InP-based materials. Using reflectivity measurements, we demonstrate a five pair GaAs/AlAs-based DBR grown on an InP substrate that reflects wavelengths between 1.4 and 2.3 μm up to 95%. © 1999 American Institute of Physics.
Show PACS
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.60.By Design of specific laser systems
42.79.Bh Lenses, prisms and mirrors
81.65.Mq Oxidation
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Displacement measurement and surface profiling using semi-insulating photoconductive semiconductors and linearly frequency-ramped lasers

Feng Jin, Jacob B. Khurgin, Suhdir Trivedi, Chen-Chia Wang, and Esam Gad

Appl. Phys. Lett. 75, 1374 (1999); http://dx.doi.org/10.1063/1.124698 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Target displacement measurement and surface profiling are demonstrated experimentally using coherence frequency domain reflectometry and the photo-emf optical difference frequency sensor that was recently shown to generate steady state dc photocurrents linearly proportional to the optical frequency differences between two laser beams interfering inside semi-insulating photoconductive semiconductors. The simplicity and spatial adaptivity of photo-emf optical frequency sensors eliminate the stringent requirements of optical alignment and calculation-intensive signal processing found in conventional coherence frequency domain reflectometry systems. © 1999 American Institute of Physics.
Show PACS
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)
07.60.Hv Refractometers and reflectometers
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
72.40.+w Photoconduction and photovoltaic effects
42.79.Nv Optical frequency converters
back to top
RSS Feeds

Polarization analysis of diffracted orders from a birefringence grating recorded on azobenzene containing polymer

F. Lagugné Labarthet, P. Rochon, and A. Natansohn

Appl. Phys. Lett. 75, 1377 (1999); http://dx.doi.org/10.1063/1.124699 (3 pages) | Cited 45 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polarization analyses of transmitted and first-diffracted orders have been performed on photoinduced gratings in azopolymers. The polarization states of diffracted orders depend strongly on irradiation time because of the contribution from both a phase grating at short time and a surface relief grating at longer time. These results are nicely explained using a Jones’ matrix approach which predicts the polarization states of transmitted and diffracted orders of polarization holographic gratings. © 1999 American Institute of Physics.
Show PACS
42.40.Eq Holographic optical elements; holographic gratings
78.20.Fm Birefringence
42.70.Jk Polymers and organics
42.79.Dj Gratings

1.54 μm electroluminescence from erbium (III) tris(8-hydroxyquinoline) (ErQ)-based organic light-emitting diodes

R. J. Curry and W. P. Gillin

Appl. Phys. Lett. 75, 1380 (1999); http://dx.doi.org/10.1063/1.124700 (3 pages) | Cited 86 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Organic light-emitting diodes have been fabricated using erbium tris(8-hydroxyquinoline) as the emitting layer and N, N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine as the hole-transporting layer. Room-temperature electroluminescence was observed at 1.54 μm due to intra-atomic transitions between the 4I13/2 and 4I15/2 levels in the Er3+ ion. These results suggest a possible route to producing a silicon-compatible 1.54 μm source technology. © 1999 American Institute of Physics.  
Show PACS
78.60.Fi Electroluminescence
85.60.Jb Light-emitting devices
73.61.Ph Polymers; organic compounds
78.66.Qn Polymers; organic compounds

Local vibrational modes as a probe of activation process in p-type GaN

H. Harima, T. Inoue, S. Nakashima, M. Ishida, and M. Taneya

Appl. Phys. Lett. 75, 1383 (1999); http://dx.doi.org/10.1063/1.124701 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Raman spectra for a series of Mg-doped GaN films grown by metal organic chemical vapor deposition and annealed in N2 ambiance at different temperatures have been investigated. Some local vibrational modes related to hydrogen were observed, showing drastic changes with the annealing temperature. The spectra show clearly that H impurities incorporated in as-grown films, which passivate Mg acceptors, are released from the Mg–N bonding at above ∼ 600 °C, and diffuse in the film to form new chemical bondings. We have also observed a local mode related to activated Mg acceptors. This mode is conveniently used as a probe of the activation process of Mg acceptors. © 1999 American Institute of Physics.
Show PACS
78.30.Fs III-V and II-VI semiconductors
78.66.Fd III-V semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
73.20.Hb Impurity and defect levels; energy states of adsorbed species
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
63.20.Pw Localized modes

Coplanar alignment of mesogenic moieties in a photocrosslinked liquid crystalline polymer film containing cinnamoyl groups

Nobuhiro Kawatsuki, Hirofumi Takatsuka, and Tohei Yamamoto

Appl. Phys. Lett. 75, 1386 (1999); http://dx.doi.org/10.1063/1.124702 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Coplanar alignment of mesogenic groups using polymer films of a methacrylate comprising a photocrosslinkable 4′-(2-cinnamoyloxyethoxy)-biphenyl group and a photoinactive 4-cyanobiphenyl group was realized by slantwise ultraviolet (UV) irradiation. Slantwise absorption measurement revealed that an orientational plane of the mesogenic groups was perpendicular to direction of the UV light propagation. The orientational angle and the ellipsoid of refractive index of the film could be regulated by changing the irradiation angle and degree of polarization of the UV exposure, respectively. © 1999 American Institute of Physics.
Show PACS
61.30.-v Liquid crystals
61.25.H- Macromolecular and polymers solutions; polymer melts
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
82.50.-m Photochemistry
68.15.+e Liquid thin films

Reduced oxygen diffusion through beryllium doped platinum electrodes

R. Stumpf, C.-L. Liu, and C. Tracy

Appl. Phys. Lett. 75, 1389 (1999); http://dx.doi.org/10.1063/1.124703 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using first principles electronic structure calculations we screen nine elements for their potential to retard oxygen diffusion through polycrystalline Pt (p-Pt) films. We determine that O diffuses preferentially as interstitial along Pt grain boundaries (GBs). The calculated barriers are compatible with experimental estimates. We find that Be controls O diffusion through p-Pt. Beryllium segregates to Pt GBs at interstitial (i) and substitutional (s) sites. i-Be is slightly less mobile than O and it repels O, thus stuffing the GB. s-Be has a high diffusion barrier and it forms strong bonds to O, trapping O in the GB. Experiments confirm our theoretical predictions. © 1999 American Institute of Physics.
Show PACS
66.30.J- Diffusion of impurities
71.15.-m Methods of electronic structure calculations
61.72.Mm Grain and twin boundaries
64.75.-g Phase equilibria
61.72.J- Point defects and defect clusters
68.55.-a Thin film structure and morphology

Dose dependence of microstructural evolution in oxygen-ion-implanted silicon carbide

Manabu Ishimaru and Kurt E. Sickafus

Appl. Phys. Lett. 75, 1392 (1999); http://dx.doi.org/10.1063/1.124704 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Transmission electron microscopy (TEM) and Rutherford backscattering spectroscopy and ion channeling (RBS/C) have been used to characterize the microstructures and damage distributions in oxygen-ion-implanted silicon carbide (SiC). 6H–SiC single crystals with [0001] orientation were irradiated with 180 keV O+ ions at 650 °C to fluences ranging from 0.2×1018 to 1.4×1018/cm2. No continuous buried amorphous layer was formed in the specimen with 0.2×1018 O+/cm2, although there were striated regions consisting of amorphous and crystalline structures at depth between 200 and 300 nm. A continuous buried amorphous layer appeared above 0.4×1018 O+/cm2, and the amorphous regions grew in size with increasing fluence. TEM and RBS/C results indicated that microstructures and elemental distributions change drastically between 0.7×1018 and 1.4×1018 O+/cm2. © 1999 American Institute of Physics.
Show PACS
61.82.Fk Semiconductors
61.72.up Other materials
61.80.Jh Ion radiation effects
61.72.J- Point defects and defect clusters
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
82.80.Yc Rutherford backscattering (RBS), and other methods of chemical analysis

Atomic force microscopy phase imaging of conductive polymer blends with ultralow percolation threshold

Jérôme Planès, Yves Samson, and Yasmina Cheguettine

Appl. Phys. Lett. 75, 1395 (1999); http://dx.doi.org/10.1063/1.124705 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Tapping-mode atomic force microscopy is used to image the conducting network of polyaniline inside organic blends. The greater stiffness of the conducting polymer phase with respect to the matrix leads to good resolution phase contrast imaging. Cross-section images provide a unique insight in the distribution of the conductive phase within the matrix. © 1999 American Institute of Physics.
Show PACS
61.41.+e Polymers, elastomers, and plastics
72.15.Nj Collective modes (e.g., in one-dimensional conductors)
73.61.Ph Polymers; organic compounds
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy

Alkali metal coactivators in SrS: Cu,F thin-film electroluminescent devices

P. D. Keir, J. F. Wager, B. L. Clark, D. Li, and D. A. Keszler

Appl. Phys. Lett. 75, 1398 (1999); http://dx.doi.org/10.1063/1.124706 (3 pages) | Cited 17 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A unique approach for obtaining bright and efficient saturated green phosphors for alternating-current thin-film electroluminescent (ACTFEL) device applications is presented. The approach involves color-shifting blue SrS:Cu,F ACTFEL phosphors into the green region of the spectrum via the incorporation of alkali metal ions into the SrS lattice. Alkali metals are incorporated into SrS:Cu,F phosphors by using LiF, NaF, KF, RbF, or CsF coactivators. The best result to date is obtained by using a KF coactivator and results in a saturated green brightness and efficiency of 52.7 cd/m2 and 0.973 lm/W (at a frequency of 60 Hz and an overvoltage of 40 V). In addition to providing a color shift, the alkali-metal fluorides improve the overall performance of the ACTFEL device by increasing the magnitude of the electric field and its uniformity across the phosphor through suppression of positive space charge. © 1999 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
85.60.Pg Display systems
78.60.Fi Electroluminescence
78.66.Nk Insulators

Antisite defects of Bi2Te3 thin films

Sunglae Cho, Yunki Kim, Antonio DiVenere, George K. Wong, John B. Ketterson, and Jerry R. Meyer

Appl. Phys. Lett. 75, 1401 (1999); http://dx.doi.org/10.1063/1.124707 (3 pages) | Cited 34 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have successfully grown Bi2Te3 thin films on CdTe(111)B using molecular-beam epitaxy. Structural and transport properties have been investigated using in situ reflection high-energy electron diffraction, θ–2θ x-ray diffraction analysis, thermopower, and Hall measurements. Both the crystallinity and the transport are found to be strongly affected by nonstoichiometry. The most stoichiometric sample had a high crystallinity, high thermopower, and high electron mobility. However, Bi2Te3 films with excess Te had a reduced lattice constant, poorer crystallinity, reduced magnitude of the thermopower, and reduced mobility. All of these observations can be explained in terms of antisite defects in which excess Te occupies Bi lattice sites and behaves as a n-type dopant. © 1999 American Institute of Physics.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
73.61.Le Other inorganic semiconductors
61.72.J- Point defects and defect clusters
73.50.Lw Thermoelectric effects
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
61.66.Bi Elemental solids
61.66.Dk Alloys
73.50.Dn Low-field transport and mobility; piezoresistance

Metal diffusion from electrodes in organic light-emitting diodes

S. T. Lee, Z. Q. Gao, and L. S. Hung

Appl. Phys. Lett. 75, 1404 (1999); http://dx.doi.org/10.1063/1.124708 (3 pages) | Cited 117 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metal diffusion from magnesium–silver cathodes and indium–tin–oxide anodes in organic light-emitting diodes has been investigated. Magnesium showed no substantial diffusion under device operation and had no significant effects on luminance decay with operation time. Indium was immobile in storage at room temperature, while indium penetration into organic layers was observed after device operation. The presence of indium in organic films showed a correlation with performance degradation. © 1999 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
66.30.J- Diffusion of impurities
78.66.Qn Polymers; organic compounds
78.60.Fi Electroluminescence
back to top
RSS Feeds

Determination of the energy-dependent conduction band mass in SiO2

R. Ludeke, E. Cartier, and Andreas Schenk

Appl. Phys. Lett. 75, 1407 (1999); http://dx.doi.org/10.1063/1.124709 (3 pages) | Cited 19 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The energy dependence of the conduction band mass in amorphous SiO2 was deduced from quantum interference oscillations in the ballistic electron emission microscope current, and separately from Monte Carlo simulations of the electron mean free paths obtained by internal photoemission. The results imply a strong nonparabolicity of the conduction band of SiO2. © 1999 American Institute of Physics.
Show PACS
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
71.23.An Theories and models; localized states
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
73.50.Fq High-field and nonlinear effects
71.38.-k Polarons and electron-phonon interactions

Reduction of band-gap energy in GaNAs and AlGaNAs synthesized by N+ implantation

W. Shan, K. M. Yu, W. Walukiewicz, J. W. Ager, E. E. Haller, and M. C. Ridgway

Appl. Phys. Lett. 75, 1410 (1999); http://dx.doi.org/10.1063/1.124951 (3 pages) | Cited 49 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the optical properties of nitrogen implanted GaAs and AlGaAs samples. The fundamental band-gap energy has been found to decrease with the increasing N+ implantation dose in a manner similar to that commonly observed in GaNAs and GaInNAs alloys grown by molecular beam epitaxy or metal organic chemical vapor deposition. Our results indicate that GaNxAs1−x and AlxGa1−xNyAs1−y alloys can be formed by implantation of nitrogen followed by appropriate postimplantation annealing treatments. As inferred from the magnitude of the band gap shift, the percentage of the implanted N atoms incorporated on the substitutional As sites is estimated to be around 12%. © 1999 American Institute of Physics.
Show PACS
61.72.uj III-V and II-VI semiconductors
81.05.Ea III-V semiconductors
71.20.Nr Semiconductor compounds
78.40.Fy Semiconductors
78.66.Fd III-V semiconductors
61.72.Cc Kinetics of defect formation and annealing

Normal-incidence infrared photoconductivity in Si p-i-n diode with embedded Ge self-assembled quantum dots

A. I. Yakimov, A. V. Dvurechenskii, Yu. Yu. Proskuryakov, A. I. Nikiforov, O. P. Pchelyakov, S. A. Teys, and A. K. Gutakovskii

Appl. Phys. Lett. 75, 1413 (1999); http://dx.doi.org/10.1063/1.124710 (3 pages) | Cited 64 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Room-temperature infrared photoconductivity in a single layer of Ge self-assembled quantum dots incorporated into silicon p-i-n diode is reported. An in-plane polarized photocurrent response with two bias controlled maxima at 2.9 μm and at 1.7 μm wavelength has been observed. The two kinds of absorption driven by reverse bias in opposite ways are ascribed to the intraband hole bound-to-continuum transition and to the interband excitonic transition. © 1999 American Institute of Physics.
Show PACS
73.50.Pz Photoconduction and photovoltaic effects
73.61.Cw Elemental semiconductors
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors

Annealing behavior of p-type Ga0.892In0.108NxAs1−x (0 ⩽ X ⩽ 0.024) grown by gas-source molecular beam epitaxy

H. P. Xin, C. W. Tu, and M. Geva

Appl. Phys. Lett. 75, 1416 (1999); http://dx.doi.org/10.1063/1.124711 (3 pages) | Cited 46 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
P-type, Be-doped GaInNAs layers (1100 Å thick) are grown on GaAs substrates by gas-source molecular beam epitaxy with a nitrogen radical beam source. High-resolution x-ray rocking curves show that the Ga0.892In0.108NxAs1−x peak shifts closer to the GaAs substrate peak with increasing N concentration, indicating reduced strain. After rapid thermal annealing (RTA) at 700 °C for 10 s, the Ga0.892In0.108As sample suffers strain relaxation, but the N-containing samples remain pseudomorphically strained, suggesting better thermal stability of GaInNAs. The wavelength of room-temperature photoluminescence redshifts from 0.988 to 1.276 μm, due to large band gap bowing, with N concentration increased from 0 to 0.024. Secondary ion mass spectrometry results show no Be diffusion, but hydrogen incorporation alongside N. The free carrier concentration is decreased by one order of magnitude mainly due to H passivation, but after RTA at 700 °C, it is increased to half that of GaInAs due to the reduced H concentration. The product of carrier concentration and Hall mobility is increased from one-tenth to about half that of the GaInAs sample. © 1999 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
61.72.Cc Kinetics of defect formation and annealing
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
78.66.Fd III-V semiconductors
73.61.Ey III-V semiconductors
78.55.Cr III-V semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
81.65.Rv Passivation
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
68.60.Dv Thermal stability; thermal effects
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close