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 Aug 1997

Volume 71, Issue 7, pp. 861-986

Page 1 of 2 Pages Next Page | Jump to Page

Integral coupler/resonator for silicon-based switching and modulation

Amy E. Bieber and T. G. Brown

Appl. Phys. Lett. 71, 861 (1997); http://dx.doi.org/10.1063/1.119670 (3 pages)

Full Text: | Download PDF

Show Abstract
An optically resonant periodic electrode structure designed as a combined waveguide coupler/Bragg reflector can function as an optical or optoelectronic switch. We present experimental results showing self-modulation of the reflectivity from such a structure using Nd:YAG laser pulses, and show self-modulation at lower intensities using an optically resonant periodic electrode structure equipped with a central phase shift. © 1997 American Institute of Physics.
Show PACS
85.60.-q Optoelectronic devices
42.60.Fc Modulation, tuning, and mode locking
42.79.Hp Optical processors, correlators, and modulators
72.80.Cw Elemental semiconductors
84.32.Dd Connectors, relays, and switches

Dual-wavelength laser emission from a coupled semiconductor microcavity

P. Pellandini, R. P. Stanley, R. Houdré, U. Oesterle, M. Ilegems, and C. Weisbuch

Appl. Phys. Lett. 71, 864 (1997); http://dx.doi.org/10.1063/1.119671 (3 pages) | Cited 52 times

Full Text: | Download PDF

Show Abstract
We report photopumped operation of a monolithic coupled semiconductor microcavity laser. The structure consists of two λ-sized GaAs vertical cavities, one on top of the other, coupled together through a common mirror. Due to a wedge induced into each cavity, the detuning between the cavities can be continuously varied when moving across the sample. Depending on the detuning, laser action is simultaneously achieved at two different wavelengths or occurs only at one wavelength. At resonance, we observe coupled dual-wavelength laser emission at two widely spaced wavelengths (13 nm) with the same threshold and same dependence on pump power. © 1997 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
81.05.Ea III-V semiconductors
42.60.By Design of specific laser systems

Origin of optical nonlinearity for PbO, TiO2, K2O, and SiO2 optical glasses

Xinhua Zhu, Qi Li, Naiben Ming, and Zhongyan Meng

Appl. Phys. Lett. 71, 867 (1997); http://dx.doi.org/10.1063/1.119672 (3 pages) | Cited 23 times

Full Text: | Download PDF

Show Abstract
The nonlinear optical properties for the PbO, TiO2, K2O, and SiO2 system have been measured by the Z-scan method. The magnitude and sign of the nonlinear refractive index n2 were determined, as was the negative sign, which indicated a self-defocusing optical nonlinearity. Two optical absorption bands at 540 and 660 nm, respectively, are observed in the optical absorption spectra. The sources of the absorption bands are attributed to the 3d-shell electronic transitions of Ti3+ ions from the ground state to the excited states. The origin of the negative nonlinear refractive index was the contribution of resonant electronic transition processes, which can cancel the positive nonresonant refractive index that mainly resulted from the hyperpolarizabilities of the Pb–O and Ti–O pairs. © 1997 American Institute of Physics.
Show PACS
42.70.Ce Glasses, quartz
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
42.65.-k Nonlinear optics

Photoconductor gain mechanisms in GaN ultraviolet detectors

E. Muñoz, E. Monroy, J. A. Garrido, I. Izpura, F. J. Sánchez, M. A. Sánchez-García, E. Calleja, B. Beaumont, and P. Gibart

Appl. Phys. Lett. 71, 870 (1997); http://dx.doi.org/10.1063/1.119673 (3 pages) | Cited 57 times

Full Text: | Download PDF

Show Abstract
GaN photoconductive detectors have been fabricated on sapphire substrates by metal organic vapor phase epitaxy and gas-source molecular beam epitaxy on Si (111) substrates. The photodetectors showed high photoconductor gains, a very nonlinear response with illuminating power, and an intrinsic nonexponential photoconductance recovery process. A novel photoconductor gain mechanism is proposed to explain such results, based on a modulation of the conductive volume of the layer. © 1997 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
72.40.+w Photoconduction and photovoltaic effects
73.50.Pz Photoconduction and photovoltaic effects
73.61.Ey III-V semiconductors
72.80.Ey III-V and II-VI semiconductors
81.05.Ea III-V semiconductors

Optical dispersion of the refractive index modulation in low Tg photorefractive polymers

Sandalphon, J. F. Wang, B. Kippelen, and N. Peyghambarian

Appl. Phys. Lett. 71, 873 (1997); http://dx.doi.org/10.1063/1.119674 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
We measure at different wavelengths the linear and nonlinear optical properties of a new chromophore for photorefractive applications by means of frequency-dependent ellipsometry experiments. We show that the optical dispersion of the refractive index modulation responsible for the high diffraction efficiency in low Tg polymers can be described by a two-level model. © 1997 American Institute of Physics.
Show PACS
42.70.Jk Polymers and organics
42.70.Mp Nonlinear optical crystals
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
42.65.-k Nonlinear optics
64.70.P- Glass transitions of specific systems
64.70.Q- Theory and modeling of the glass transition
07.60.Fs Polarimeters and ellipsometers

A diode-pumped, high gain, planar waveguide, Nd:Y3Al5O12 amplifier

D. P. Shepherd, C. T. A. Brown, T. J. Warburton, D. C. Hanna, A. C. Tropper, and B. Ferrand

Appl. Phys. Lett. 71, 876 (1997); http://dx.doi.org/10.1063/1.119675 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We report the use of a 5-mm-long planar Nd:yttrium aluminum garnet waveguide grown by liquid-phase epitaxy as an amplifier at 1.064 μm. In a double-pass configuration pumped by a 1.2 W diode laser, small signal gains of 686 (28 dB) have been observed and efficient power extraction demonstrated with output powers of up to 290 mW being obtained. © 1997 American Institute of Physics.
Show PACS
42.60.By Design of specific laser systems
42.79.Gn Optical waveguides and couplers
42.82.Et Waveguides, couplers, and arrays
42.55.Rz Doped-insulator lasers and other solid state lasers

Improved laser modulation response by frequency modulation to amplitude modulation conversion in transmission through a fiber grating

Matt McAdams, Eva Peral, Dan Provenzano, W. K. Marshall, and Amnon Yariv

Appl. Phys. Lett. 71, 879 (1997); http://dx.doi.org/10.1063/1.119676 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
We have demonstrated that transmission through a fiber grating can increase the system response of a directly modulated semiconductor laser by over 7 dB at all modulation frequencies up to 25 GHz. When combined with dispersive optical fiber, the grating produced a system response that was larger, flatter, and had a larger bandwidth, providing a frequency-domain demonstration of dispersion compensation through an unchirped grating. The effect can be understood as frequency modulation to amplitude modulation conversion by the grating, and was accurately predicted by a Fourier domain analysis of the laser signal and grating. © 1997 American Institute of Physics.
Show PACS
42.60.Fc Modulation, tuning, and mode locking
42.55.Px Semiconductor lasers; laser diodes
42.79.Dj Gratings
42.81.Dp Propagation, scattering, and losses; solitons
02.30.Nw Fourier analysis

Ultrafast-laser driven micro-explosions in transparent materials

E. N. Glezer and E. Mazur

Appl. Phys. Lett. 71, 882 (1997); http://dx.doi.org/10.1063/1.119677 (3 pages) | Cited 236 times

Full Text: | Download PDF

Show Abstract
We initiate micro-explosions inside fused silica, quartz, sapphire, and other transparent materials using tightly focused 100 fs laser pulses. In the micro-explosions, material is ejected from the center, forming a cavity surrounded by a region of compacted material. We examine the resulting structures with optical microscopy, diffraction, and atomic force microscopy of internal cross sections. We find the structures have a diameter of only 200–250 nm, which we attribute to strong self-focusing of the laser pulse. These experiments probe a unique regime of light propagation inside materials at intensities approaching 1021 W/m2, the electron ionization that accompanies it, and the material response to extreme pressure and temperature conditions. The micro-explosions also provide a novel technique for internal microstructuring of transparent materials. © 1997 American Institute of Physics.
Show PACS
61.82.Ms Insulators
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
82.33.Vx Reactions in flames, combustion, and explosions
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
61.72.-y Defects and impurities in crystals; microstructure

Observation of oxide/Si(001)-interface during layer-by-layer oxidation by scanning reflection electron microscopy

S. Fujita, H. Watanabe, S. Maruno, M. Ichikawa, and T. Kawamura

Appl. Phys. Lett. 71, 885 (1997); http://dx.doi.org/10.1063/1.120567 (3 pages) | Cited 23 times

Full Text: | Download PDF

Show Abstract
We have found that terrace contrast of oxidized Si(001) substrate observed with a scanning reflection electron microscopy (SREM) is reversed by progress in thermal oxidation by one atomic layer of Si. The cause for such terrace contrast reversion is that reflection electron intensity depends on Si-bond direction at oxide/Si interface. This fact was confirmed by calculations based on a multiple scattering theory. The motion of oxide/Si-bulk interface can be, thus, observed by SREM. The reversion and continuous change of the terrace contrast indicate that oxidation occurs monolayer by monolayer on Si(001) substrate. © 1997 American Institute of Physics.
Show PACS
81.65.Mq Oxidation
68.35.Ct Interface structure and roughness
81.05.Cy Elemental semiconductors
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Nanoscale caliper for direct measurement of scanning force microscopy probes

Fabio Biscarini and Pablo Levy

Appl. Phys. Lett. 71, 888 (1997); http://dx.doi.org/10.1063/1.119678 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We show the possibility to measure the effective tip shape and the lateral resolution of a scanning force microscopy (SFM) probe on the nanometer-scale directly from SFM images of SiC(0001). On this surface there are grooves 10–100-nm-wide related to cleavage planes. The SFM tip penetrates the groove but does not reach the bottom since its side walls touch both rims. The width of the narrowest groove resolved is the lateral resolution. The apparent topography across a groove yields directly the tip radius of curvature in excellent agreement with the values estimated from scanning electron micrographs. © 1997 American Institute of Physics.
Show PACS
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
68.35.B- Structure of clean surfaces (and surface reconstruction)
87.64.Dz Scanning tunneling and atomic force microscopy

Synthesis of yttrium oxide thin films with and without the use of organic self-assembled monolayers

M. Agarwal, M. R. DeGuire, and A. H. Heuer

Appl. Phys. Lett. 71, 891 (1997); http://dx.doi.org/10.1063/1.119679 (3 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
Thin Y-containing films have been deposited at 80 °C from aqueous solutions of YNO3⋅5H2O and urea on bare single crystal Si wafers, and on Si wafers coated with sulfonate-functionalized organic self-assembled monolayers. The as-deposited films are believed to be an amorphous yttrium basic carbonate and can be completely transformed at 600 °C in air to crystalline Y2O3. Capacitance–voltage measurements on these films showed good dielectric properties, with a relative permitivity of 18, more than a factor of four higher than that of SiO2. © 1997 American Institute of Physics.
Show PACS
73.61.Ng Insulators
77.22.Ch Permittivity (dielectric function)
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
64.70.D- Solid-liquid transitions

Influence of nanoscale surface curvature on prenucleation phenomena in chemical vapor deposition diamond growth

O. A. Louchev, Y. Sato, and P. A. Dennig

Appl. Phys. Lett. 71, 894 (1997); http://dx.doi.org/10.1063/1.119680 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
The problem of adsorption desorption of methyl radicals on a surface with nanoscale curvature is numerically studied for typical chemical vapor deposition diamond growth conditions. Surface profiles with concave nanoscale curvature lead to an increase in the energy of adsorption, which can enhance the nucleation of the new phase on the substrates. Moreover, the nanoscale curvature is even able to provoke a nucleation of the new phase on substrates which do not have an affinity for nucleation. © 1997 American Institute of Physics.
Show PACS
81.05.ub Fullerenes and related materials
81.05.Cy Elemental semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.-a Thin film structure and morphology
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.43.-h Chemisorption/physisorption: adsorbates on surfaces

Fully oriented decagonal quasicrystalline thin films on crystalline substrates

Guohong Li, Dianlin Zhang, Hongwei Jiang, Wuyan Lai, Wei Liu, and Yunping Wang

Appl. Phys. Lett. 71, 897 (1997); http://dx.doi.org/10.1063/1.119681 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Fully oriented AlCuCo decagonal quasicrystalline films on crystalline substrates were successfully prepared by multitarget magnetron sputtering followed by postannealing. The width of the rocking curve competes with that of a single crystal. To explain the result, we suggest that the full orientation of the films originates from the fact that only one atomic flat plane of the structure is available to match the flat surface of the substrate, which gives a minimum interface free energy. © 1997 American Institute of Physics.
Show PACS
61.44.Br Quasicrystals
68.55.-a Thin film structure and morphology
81.40.Gh Other heat and thermomechanical treatments
65.20.-w Thermal properties of liquids
65.40.gd Entropy
68.35.Md Surface thermodynamics, surface energies

Diffusion of zinc acceptors in InAsP by the metal-organic vapor-phase diffusion technique

Morio Wada, Kyoko Izumi, and Katsutoshi Sakakibara

Appl. Phys. Lett. 71, 900 (1997); http://dx.doi.org/10.1063/1.119682 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
Diffusion of zinc acceptors in InAsP by a metal-organic vapor-phase diffusion technique, whereby a low-pressure metal-organic vapor-phase epitaxy with dimethylzinc and phosphine is utilized as an open tube diffusion system, is demonstrated to accurately control the diffusion depth in the submicrometer range. The annealing effect on the zinc diffusion profiles in InAsP was found to be the activation of zinc acceptors similar to that in InP, but the maximum hole concentration of 1×1019 cm−3 for the zinc diffusion in InAsP was achieved. © 1997 American Institute of Physics.
Show PACS
61.72.uj III-V and II-VI semiconductors
81.05.Ea III-V semiconductors
66.30.J- Diffusion of impurities
61.72.S- Impurities in crystals
61.72.Cc Kinetics of defect formation and annealing
81.40.Gh Other heat and thermomechanical treatments
71.55.Eq III-V semiconductors
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Epitaxial growth of Y2O3 films on Si(100) without an interfacial oxide layer

S. C. Choi, M. H. Cho, S. W. Whangbo, C. N. Whang, S. B. Kang, S. I. Lee, and M. Y. Lee

Appl. Phys. Lett. 71, 903 (1997); http://dx.doi.org/10.1063/1.119683 (3 pages) | Cited 50 times

Full Text: | Download PDF

Show Abstract
Heteroepitaxial Y2O3 films were grown on Si(100) substrates by the technique of reactive ionized cluster beam deposition. The crystallinity of the films was investigated with reflection high energy electron diffraction (RHEED), glancing angle x-ray diffraction (GXRD), and the interface was examined by high resolution transmission electron microscopy (HRTEM). Under the condition of 5 kV acceleration voltage at the substrate temperature of 800 °C, the Y2O3 film grows epitaxially on the Si(100) substrate. RHEED and GXRD results revealed that the epitaxial relationship between Y2O3 and Si(100) is Y2O3(110)//Si(100), and HRTEM observation showed a sharp interface without an amorphous layer. © 1997 American Institute of Physics.
Show PACS
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.-a Thin film structure and morphology
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.35.Ct Interface structure and roughness
68.35.B- Structure of clean surfaces (and surface reconstruction)

Compositional inhomogeneity and immiscibility of a GaInN ternary alloy

Akihiro Wakahara, Takashi Tokuda, Xiao-Zhong Dang, Susumu Noda, and Akio Sasaki 

Appl. Phys. Lett. 71, 906 (1997); http://dx.doi.org/10.1063/1.119684 (3 pages) | Cited 37 times

Full Text: | Download PDF

Show Abstract
Compositional inhomogeneity in a GaInN ternary alloy layer is investigated. A theoretical estimation of the interaction parameter based on the delta lattice parameter suggests that the immiscibility of InN in a nitride alloy is very strong. We investigate the compositional splitting and the existence of InN inclusion in the GaInN epilayer grown on sapphire (0001) substrates. The mechanism of compositional inhomogeneity is discussed. © 1997 American Institute of Physics.
Show PACS
61.66.Bi Elemental solids
61.66.Dk Alloys
64.75.-g Phase equilibria
61.66.Fn Inorganic compounds
68.55.Nq Composition and phase identification

Characterization of zinc blende InxGa1−xN grown by radio frequency plasma assisted molecular beam epitaxy on GaAs (001)

J. R. Müllhäuser, B. Jenichen, M. Wassermeier, O. Brandt, and K. H. Ploog

Appl. Phys. Lett. 71, 909 (1997); http://dx.doi.org/10.1063/1.119685 (3 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
Successful growth of a cubic In0.17Ga0.83N/GaN structure exhibiting blue luminescence at temperatures up to 500 K is reported. Atomic force microscopy and x-ray diffraction are used to analyze the morphological and crystalline properties of the sample. Photoluminescence measurements reveal broad, but well defined emission with a maximum at 440–450 nm in the temperature range of 5–500 K. A line-shape analysis of the spectra, as well as measurements of the absorption coefficient, allow an estimation of the band-gap energy of the cubic In0.17Ga0.83N epilayer. © 1997 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.55.Cr III-V semiconductors
71.20.Nr Semiconductor compounds
68.55.-a Thin film structure and morphology
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Schottky barrier heights and conduction-band offsets of In1−xGaxAs1−yPy lattice matched to GaAs

Jong-Kwon Lee, Yong-Hoon Cho, Byung-Doo Choe, K. S. Kim, H. I. Jeon, H. Lim, and M. Razeghi

Appl. Phys. Lett. 71, 912 (1997); http://dx.doi.org/10.1063/1.119686 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
The Schottky barrier heights of Au/In1−xGaxAs1−yPy contacts have been determined as a function of y by the capacitance–voltage and temperature dependent current–voltage characteristics measurements. The barrier height is observed to increase as y is increased for both n- and p-type materials, with a more rapid increase for the p-type material. The compositional variation of the barrier heights for Au/n-In1−xGaxAs1−yPy is found to be identical to that of the conduction-band offsets in In1−xGaxAs1−yPy/GaAs heterojunctions. A possible cause of this phenomenon is also discussed. © 1997 American Institute of Physics.
Show PACS
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.20.At Surface states, band structure, electron density of states

Nonlinear absorption and gain in InGaAs/GaAs quantum wells

Giuliano Coli, Adriana Passaseo, Donato Greco, Roberto Cingolani, Marco Tagliaferri, Paolo di Trapani, and Alessandra Andreoni

Appl. Phys. Lett. 71, 915 (1997); http://dx.doi.org/10.1063/1.119687 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We present a detailed study of the excitonic nonlinearities in InGaAs/GaAs multiple quantum wells based on both stationary and transient pump-and-probe transmission spectroscopy. Bleaching of the excitonic resonance and free carrier gain have been observed. A quantitative analysis of the observed nonlinearity is provided by means of a rigorous solution of the Bethe–Salpeter equation for the investigated heterostructures. © 1997 American Institute of Physics.
Show PACS
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.65.-k Nonlinear optics
78.66.Fd III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.35.Cc Intrinsic properties of excitons; optical absorption spectra

Quantized conductance in a heterostructurally defined Ga0.25In0.75As/InP quantum wire

P. Ramvall, N. Carlsson, I. Maximov, P. Omling, L. Samuelson, W. Seifert, Q. Wang, and S. Lourdudoss

Appl. Phys. Lett. 71, 918 (1997); http://dx.doi.org/10.1063/1.119688 (3 pages) | Cited 39 times

Full Text: | Download PDF

Show Abstract
We report on the observation of quantized conductance up to 10 K in epitaxially regrown, heterostructurally defined, 100-nm-wide Ga0.25In0.75As/InP quantum wires. In addition to the plateaus at integer steps of 2e2/h, we observe plateaus at 0.2(2e2/h), 0.7(2e2/h), and 1.5(2e2/h), indicating spin polarization at zero magnetic field. Of these, the first two plateaus appear to evolve into one at around 0.5(2e2/h) when the sample is subjected to a magnetic field parallel to the quantum wire. The observation of quantized conductance is made possible by the substantial improvement in the quality of the interface by regrowth. © 1997 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.23.-b Electronic transport in mesoscopic systems

Optical properties of Si-doped GaN

E. F. Schubert, I. D. Goepfert, W. Grieshaber, and J. M. Redwing

Appl. Phys. Lett. 71, 921 (1997); http://dx.doi.org/10.1063/1.119689 (3 pages) | Cited 105 times

Full Text: | Download PDF

Show Abstract
The optical properties of n-type GaN are investigated for Si doping concentrations ranging from 5×1016 to 7×1018 cm−3. The photoluminescence linewidth of the near-band gap optical transition increases from 47 to 78 meV as the doping concentration is increased. The broadening is modeled in terms of potential fluctuations caused by the random distribution of donor impurities. Good agreement is found between experimental and theoretical results. The intensity of the near-band-gap transition increases monotonically as the doping concentration is increased indicating that nonradiative transitions dominate at a low doping density. The comparison of absorption, luminescence, reflectance, and photoreflectance measurements reveals the absence of a Stokes shift at room temperature demonstrating the intrinsic nature of the near-band edge transition. © 1997 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
61.72.S- Impurities in crystals
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
71.55.Eq III-V semiconductors
71.20.Nr Semiconductor compounds
78.20.-e Optical properties of bulk materials and thin films
78.40.Fy Semiconductors

Enhanced Sb segregation in surfactant-mediated-heteroepitaxy: High-mobility, low-doped Ge on Si

D. Reinking, M. Kammler, M. Horn-von Hoegen, and K. R. Hofmann

Appl. Phys. Lett. 71, 924 (1997); http://dx.doi.org/10.1063/1.119690 (3 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
Surfactant-mediated epitaxy (SME) allows the growth of smooth, continuous, relaxed, and principally defect free Ge films directly on Si(111); however, the very high surfactant doping level in the range of the solid solubility limit made them unacceptable for most device applications. By using high temperature SME we have reduced the Sb surfactant background doping level by more than three orders of magnitude. This is attributed to an enhanced surfactant segregation without kinetic limitations. The low Sb incorporation has been determined by an electrical characterization: An electron concentration of 1.1×1016 cm−3 and a very high electron Hall mobility of 3100 cm2/V s at 300 K (12 300 cm2/V s at 77 K) suggest an interesting potential of SME grown Ge films for future device applications. © 1997 American Institute of Physics.
Show PACS
81.05.Cy Elemental semiconductors
81.15.Np Solid phase epitaxy; growth from solid phases
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.Cw Elemental semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
68.35.Fx Diffusion; interface formation
64.75.-g Phase equilibria
81.30.Mh Solid-phase precipitation

Photoluminescence and time-resolved photoluminescence characteristics of InxGa(1−x)As/GaAs self-organized single- and multiple-layer quantum dot laser structures

K. Kamath, N. Chervela, K. K. Linder, T. Sosnowski, H-T. Jiang, T. Norris, J. Singh, and P. Bhattacharya

Appl. Phys. Lett. 71, 927 (1997); http://dx.doi.org/10.1063/1.119691 (3 pages) | Cited 38 times

Full Text: | Download PDF

Show Abstract
The characteristics of ground and excited state luminescent transitions in In0.4Ga0.6As/GaAs and In0.35Ga0.65As/GaAs self-organized single- and multiple-layer quantum dots forming the active regions of lasers have been studied as a function of incident excitation intensity, temperature and number of dot layers. The results have been correlated with molecular beam epitaxial growth conditions. The threshold excitation density for the saturation of the ground state increases with the number of dot layers and no saturation is observed in samples with more than six dot layers up to an excitation power density of 2 kW/cm2. The luminescent decay times for the ground and excited states are around 700 and 250 ps, respectively, almost independent of the number of dot layers. © 1997 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
42.55.Px Semiconductor lasers; laser diodes
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
81.05.Ea III-V semiconductors
73.61.Ey III-V semiconductors
78.47.-p Spectroscopy of solid state dynamics
73.20.At Surface states, band structure, electron density of states

Temperature dependent electron-hole recombination in polymer light-emitting diodes

P. W. M. Blom, M. J. M. de Jong, and S. Breedijk

Appl. Phys. Lett. 71, 930 (1997); http://dx.doi.org/10.1063/1.119692 (3 pages) | Cited 98 times

Full Text: | Download PDF

Show Abstract
The current density–voltage characteristics of poly(dialkoxy p-phenylene vinylene) based polymer are investigated as a function of temperature. Model calculations show that the differences between single and double carrier devices can be well understood by taking into account a bimolecular recombination process. It is found that the bimolecular recombination is thermally activated with an identical activation energy as measured for the charge carrier mobility. This demonstrates that the recombination process is of the Langevin type, and explains why the conversion efficiency (photon/carrier) of a polymer light-emitting diode is temperature independent. © 1997 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
73.61.Ph Polymers; organic compounds
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Anisotropy of electrical and optical properties in β-Ga2O3 single crystals

Naoyuki Ueda, Hideo Hosono, Ryuta Waseda, and Hiroshi Kawazoe

Appl. Phys. Lett. 71, 933 (1997); http://dx.doi.org/10.1063/1.119693 (3 pages) | Cited 59 times

Full Text: | Download PDF

Show Abstract
Anisotropy of electrical and optical properties in β-Ga2O3 single crystals has been investigated at room temperature. The conductivity and mobility of the degenerate sample along the direction of b and c axes are 38 Ω−1 cm−1, 46 cm2 V−1 s−1, and 2.2 Ω−1 cm−1, 2.6 cm2 V−1 s−1, respectively. The absorption edges of the insulating sample for light polarized E//b and E//c were 4.79 and 4.52 eV, respectively. The rate of the band gap widening with increasing carrier concentration was much larger for E//b than E//c. The origin of these properties are discussed by considering the crystal and electronic structure of β-Ga2O3. © 1997 American Institute of Physics.
Show PACS
72.80.Jc Other crystalline inorganic semiconductors
71.20.Nr Semiconductor compounds
72.20.Fr Low-field transport and mobility; piezoresistance
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
61.66.Fn Inorganic compounds
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close