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3 Jul 1989

Volume 55, Issue 1, pp. 1-89

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Stimulated emission in quantum well laser diodes

P. Blood

Appl. Phys. Lett. 55, 1 (1989); http://dx.doi.org/10.1063/1.101745 (3 pages) | Cited 5 times

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We observe that stimulated emission from inhomogeneously pumped quantum well laser diodes is shifted down in energy compared with the subband transition energy. Measured spontaneous emission spectra show that this stimulated emission is due to band‐to‐band transitions shifted by renormalization at high injected carrier densities, and we suggest that this same mechanism explains reported observations of stimulated emission from inhomogeneously photopumped structures which previously have been interpreted as evidence for longitudinal optic (LO) phonon participation. We show that LO phonon participation cannot account for the photon energy of stimulated emission from conventional homogeneously pumped quantum well laser diodes.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
78.45.+h Stimulated emission
42.55.Px Semiconductor lasers; laser diodes
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors

Thermochromic sputter‐deposited vanadium oxyfluoride coatings with low luminous absorptance

K. A. Khan and C. G. Granqvist

Appl. Phys. Lett. 55, 4 (1989); http://dx.doi.org/10.1063/1.102388 (3 pages) | Cited 24 times

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Thin films of VOxFy were made by rf magnetron sputtering of V in Ar+O2+CF4. They were analyzed by Rutherford backscattering spectrometry and transmission electron microscopy. Optical and electrical properties changed within narrow temperature ranges. These results resemble those of thermochromic VO2, although VOxFy has significantly enhanced transmittance, lowered conductance, and marginally depressed switching temperature.
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78.66.-w Optical properties of specific thin films
73.61.Ng Insulators
81.15.Cd Deposition by sputtering
81.40.Tv Optical and dielectric properties related to treatment conditions

Femtosecond 1.4–1.6 μm infrared pulse generation at a high repetition rate by difference frequency generation

Kenji Kurokawa and Masataka Nakazawa

Appl. Phys. Lett. 55, 7 (1989); http://dx.doi.org/10.1063/1.101759 (3 pages) | Cited 13 times

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Tunable subpicosecond infrared pulses have been generated in the 1.4–1.6 μm region by mixing a 1.064 μm Nd:YAG laser pulse and a visible subpicosecond pulse from a cavity dumped, synchronously pumped dye laser. Pulses as short as 94 fs with a peak power of 8.4 kW have been obtained with a KTP crystal at a rate of 3.8 MHz.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers

High‐power, in‐phase‐mode operation from resonant phase‐locked arrays of antiguided diode lasers

L. J. Mawst, D. Botez, T. J. Roth, and G. Peterson

Appl. Phys. Lett. 55, 10 (1989); http://dx.doi.org/10.1063/1.101741 (3 pages) | Cited 18 times

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A resonant phase‐locked array of antiguides is demonstrated for the first time. A 10/11 element AlGaAs/GaAs antiguided array is grown by two‐step metalorganic chemical vapor deposition. Longitudinally, the structure consists of two noncollinear sets of antiguides separated by a half‐Talbot distance, an ensemble that acts as a spatial filter. Out‐of‐phase‐mode operation is suppressed both by this diffractive‐type spatial filter and by large interelement loss. Resonant in‐phase‐mode operation is a result of the interelement spacing corresponding to one leaky‐wave half wavelength in the lateral direction. Near the in‐phase‐mode resonance, array modes adjacent to the in‐phase‐mode are discriminated against because they have large radiation losses in the antiguided structure and significant edge diffraction losses in the spatial filter. Stable, diffraction‐limited in‐phase‐mode beam patterns are achieved to 10 times threshold and 450 mW output power.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Px Semiconductor lasers; laser diodes
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Spectral shift and distortion due to self‐phase modulation of picosecond pulses in 1.5 μm optical amplifiers

N. A. Olsson and Govind P. Agrawal

Appl. Phys. Lett. 55, 13 (1989); http://dx.doi.org/10.1063/1.101742 (3 pages) | Cited 15 times

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Picosecond pulses are observed to exhibit large frequency shifts (∼50 GHz) and spectral distortion on propagation through semiconductor laser optical amplifiers. The spectral changes are shown to result from self‐phase modulation occurring due to the carrier‐induced index changes that invariably accompany gain saturation. An analytic model for pulse amplification is presented by including the self‐phase modulation effects. Its predictions are in good agreement with the experimental results.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Fc Modulation, tuning, and mode locking
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers

Low‐threshold PbEuSeTe double‐heterostructure lasers grown by molecular beam epitaxy

Z. Feit, R. Woods, D. Kostyk, and W. Jalenak

Appl. Phys. Lett. 55, 16 (1989); http://dx.doi.org/10.1063/1.101743 (3 pages) | Cited 7 times

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Lattice‐matched double‐heterostructure (DH) PbEuSeTe lasers were grown by molecular beam epitaxy (MBE) on (100) oriented PbTe substrates. Grooved mesa structures with 17–25 μm wide stripes and 0.75 μm thick Pb1−xEuxSeyTe1−y active layers with 0≤x≤0.031 were fabricated. DH diode lasers with a PbTe active layer reached a maximum cw operation temperature of 175 K which equals the highest operation temperature achieved so far by a side optical cavity (SOC) single quantum well (SQW) PbTe/PbEuSeTe laser. The threshold current density of 3.9 A/cm2 measured for this laser at 15 K is, to our knowledge, the lowest ever published for lead salt lasers. Comparison of MBE‐grown DH lasers which utilize the lattice‐matched PbTe/PbEuSeTe system to those utilizing the nonlattice‐matched PbSe/PbEuSe system shows higher operation temperatures and by far lower threshold currents for the lattice‐matched system.
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42.55.Px Semiconductor lasers; laser diodes
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Single‐frequency tunable external‐cavity semiconductor laser using an electro‐optic birefringent modulator

A. Schremer and C. L. Tang

Appl. Phys. Lett. 55, 19 (1989); http://dx.doi.org/10.1063/1.101744 (3 pages) | Cited 2 times

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An external‐cavity semiconductor laser employing a birefringent electro‐optic modulator for wavelength tuning is described. Wide‐band tuning over 70 Å in a single frequency to residual diode modes and narrow‐band tuning over 0.42 Å to many longitudinal modes of the external cavity is demonstrated using different modulator configurations. Threshold current and quantum efficiency are nearly as good as that of the solitary laser diode.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking

Transverse modes, waveguide dispersion, and 30 ps recovery in submicron GaAs/AlAs microresonators

J. L. Jewell, S. L. McCall, A. Scherer, H. H. Houh, N. A. Whitaker, A. C. Gossard, and J. H. English

Appl. Phys. Lett. 55, 22 (1989); http://dx.doi.org/10.1063/1.101746 (3 pages) | Cited 21 times

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We have studied room‐temperature optical gating of ∼5 ps pulses in GaAs/AlAs microresonators with diameters ranging from <0.5 μm to 1.5 μm by using a high‐refractive‐index lens system having a numerical aperture of 1.3. The larger devices exhibited well‐defined transverse modes, which caused decreased modulation of the probe beam. Waveguide dispersion, present in all the devices, showed fair agreement with calculations. The smallest diameter devices (<0.5 μm) show high modulation, fully recover in <30 ps, and have their peak transmission wavelengths shifted by >500 Å compared to a large ∼10 μm nearby region.
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07.60.-j Optical instruments and equipment
42.79.-e Optical elements, devices, and systems
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.79.Gn Optical waveguides and couplers
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks

Optical fiber switch employing a Sagnac interferometer

M. C. Farries and D. N. Payne

Appl. Phys. Lett. 55, 25 (1989); http://dx.doi.org/10.1063/1.101737 (2 pages) | Cited 15 times

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Switching in less than 1 ns of an optical signal at 632 nm is demonstrated in a 1 m optical fiber Sagnac interferometer. Full signal modulation was obtained with a pump power of 24 W at a wavelength of 532 nm.
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42.81.Wg Other fiber-optical devices
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
07.60.Ly Interferometers
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Effects of frequency spreads on beam breakup instabilities in linear accelerators

D. G. Colombant and Y. Y. Lau

Appl. Phys. Lett. 55, 27 (1989); http://dx.doi.org/10.1063/1.101738 (3 pages) | Cited 12 times

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Structure mode frequency spreads are shown to have a rather different influence on beam breakup growths than betatron frequency spreads. The present analytic and numerical studies show that a finite spread in the breakup mode frequency leads to an algebraic decay of the beam breakup instabilities even if the quality factor Q→∞. Effects of stagger tuning are examined.
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41.75.Ht Relativistic electron and positron beams
52.35.Py Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.)
29.20.Ej Linear accelerators

Doppler profile measurement of Ar and Ar+ translational energies in a divergent magnetic field electron cyclotron resonance source

John S. McKillop, John C. Forster, and William M. Holber

Appl. Phys. Lett. 55, 30 (1989); http://dx.doi.org/10.1063/1.101739 (3 pages) | Cited 20 times

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High‐resolution optical emission spectroscopy has been used to measure Doppler profiles of Ar and Ar+ transitions in a divergent magnetic field electron cyclotron resonance (ECR) source, yielding average translational energies between 0.1 and 0.6 eV (Ar), and 1.0 and 2.5 eV (Ar+). ECR magnetic field configuration strongly affects Ar+ energies, although little variation with Ar pressure (0.1–1.5 mTorr) is found. The average Ar energy increases slightly with pressure. These observations suggest that thermal ion and neutral excitation primarily results from collisional degradation of directed downstream ion energies arising from the unique ambipolar potential created in ECR sources.
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52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.80.-s Electric discharges
32.70.Jz Line shapes, widths, and shifts

Time‐resolved Raman spectrum of shock‐compressed diamond

Y. M. Gupta, P. D. Horn, and C. S. Yoo

Appl. Phys. Lett. 55, 33 (1989); http://dx.doi.org/10.1063/1.101740 (3 pages) | Cited 9 times

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A method has been developed for time‐resolved Raman measurements under shock loading to examine the first‐order Raman line of diamond (ω0=1333 cm−1). The diamond samples were subjected to uniaxial strain along the [110] direction to a longitudinal stress of 121 kbar. The observed spectral changes are consistent with frequency shifts calculated according to a phenomenological model used to describe stress effects on the zone center phonons of cubic materials.
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78.30.Hv Other nonmetallic inorganics
62.20.D- Elasticity
62.50.-p High-pressure effects in solids and liquids

Kinetics of the solid‐state amorphizing reaction in thin films studied by electrical resistivity

J. B. Rubin and R. B. Schwarz

Appl. Phys. Lett. 55, 36 (1989); http://dx.doi.org/10.1063/1.101747 (3 pages) | Cited 4 times

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We deposited Ni‐Zr thin‐film multilayers by electron beam evaporation onto polished alumina substrates. The multilayers were annealed at a constant heating rate, and in situ resistance measurements made to derive the growth kinetics of amorphous NiZr alloy at the Ni/Zr interfaces. Using a simple model that relates resistance change to amorphous‐layer thickness, we derive the apparent diffusivity of nickel in amorphous Ni50Zr50, DNi =2.5×10−5 exp[−1.01(eV)/kT] cm2 s−1.
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68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
66.30.Ny Chemical interdiffusion; diffusion barriers
73.61.At Metal and metallic alloys
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Characterization of the CoGa/GaAs interface

Jane G. Zhu, C. Barry Carter, C. J. Palmstrøm, and K. C. Garrison

Appl. Phys. Lett. 55, 39 (1989); http://dx.doi.org/10.1063/1.101748 (3 pages) | Cited 12 times

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The interface between the (001) surface of GaAs and a CoGa layer grown by molecular beam epitaxy has been characterized using transmission electron microscopy in plan view and cross‐sectional view. The interface is found to consist primarily of a network of edge dislocations with Burgers vectors a[100] and a[010] (a being the lattice parameter of the CoGa). The occurrence of these Burgers vectors indicates that these misfit dislocations are nucleated in the CoGa during growth. It is clearly shown that the threading dislocations in the CoGa originate at the misfit dislocations at the interface, while the GaAs layer underneath is free of dislocation.
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68.35.Dv Composition, segregation; defects and impurities
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination

Thermomechanical fracture instability and stick‐slip crack propagation

I. L. Maksimov

Appl. Phys. Lett. 55, 42 (1989); http://dx.doi.org/10.1063/1.101749 (3 pages) | Cited 3 times

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A self‐consistent approach is proposed for the first time to describe the fracture in viscous plastic media taking into account the energy dissipation near the crack tip. The conditions are found under which slow heat‐ and stress‐stimulated crack propagation occurs. It is found that cracks of small size are unstable with respect to thermal and mechanical disturbances. It is shown that stick‐slip fracture instability due to the energy exchange between mechanical and thermal modes can take place at a certain stage of crack propagation. An estimation is obtained for the number of slips in the course of discontinuous fracture.
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62.20.M- Structural failure of materials
65.40.De Thermal expansion; thermomechanical effects
62.20.F- Deformation and plasticity
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Reduction of metal oxides by mechanical alloying

G. B. Schaffer and P. G. McCormick

Appl. Phys. Lett. 55, 45 (1989); http://dx.doi.org/10.1063/1.101750 (2 pages) | Cited 56 times

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The chemical reduction of metal oxides by mechanical alloying with a strong reducing element has been investigated. Using x‐ray diffraction to follow the reaction it was found that the mechanical alloying of CuO and Ca using toluene as a processing lubricant resulted in the formation of Cu. The mechanical alloying of CuO and ZnO together with Ca resulted in the formation of β′ brass.
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82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.35.Md Surface thermodynamics, surface energies
82.30.Hk Chemical exchanges (substitution, atom transfer, abstraction, disproportionation, and group exchange)

Influence of entropy properties on measured trap energy distributions at insulator‐semiconductor interfaces

Olof Engström

Appl. Phys. Lett. 55, 47 (1989); http://dx.doi.org/10.1063/1.102389 (3 pages) | Cited 4 times

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By using a thermodynamical approach to the ensemble of interface traps of insulator‐semiconductor interfaces, it is demonstrated that the entropy properties of the traps may have a considerable influence on measured energy distributions. Because experimentally obtained distributions are given on a free‐energy scale, thermodynamics must be utilized when comparing with theoretical distributions of eigenenergy scales. Both the U‐shaped energy distributions profiles, normally found for silicon–silicon dioxide structures, and the peaks, obtained in these distributions for samples being exposed to radiation or bias stress, would occur for reasonable entropy distributions even if the interface state distribution on an eigenenergy scale were constant.
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73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Reduction of trap concentration and interface roughness of GaAs/AlGaAs quantum wells by low growth rates in molecular beam epitaxy

Ch. Maierhofer, S. Munnix, D. Bimberg, R. K. Bauer, D. E. Mars, and J. N. Miller

Appl. Phys. Lett. 55, 50 (1989); http://dx.doi.org/10.1063/1.101751 (3 pages) | Cited 8 times

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A simultaneous reduction of interface roughness and of impurity and trap incorporation in GaAs/AlGaAs quantum wells is observed for a decrease of the molecular beam epitaxy growth rate below its standard value 1 μm/h, down to 0.1 μm/h, at a substrate temperature of 620 °C. Thus, layer quality is drastically improved at low, nonstandard growth rates. Incorporation of impurities from the background is observed to induce a transition from two‐ to three‐dimensional growth. The conclusions are based on a detailed study and line shape analysis of quantum well luminescence.
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68.35.Gy Mechanical properties; surface strains
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.55.Cr III-V semiconductors

Compositional modulation in AlxGa1−xAs epilayers grown by molecular beam epitaxy on the (111) facets of grooves in a nonplanar substrate

Michael E. Hoenk, C. W. Nieh, Howard Z. Chen, and Kerry J. Vahala

Appl. Phys. Lett. 55, 53 (1989); http://dx.doi.org/10.1063/1.102263 (3 pages) | Cited 10 times

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We report the first observation of a lateral junction formed in an alloy due to an abrupt transition from segregated to random AlGaAs alloy compositions. Al0.25Ga0.75As epilayers were grown by molecular beam epitaxy on [011] oriented grooves in a nonplanar (100) GaAs substrate. A quasi‐periodic modulation of the aluminum concentration occurs spontaneously in material grown on the (111) facets of the groove, with a period of 50–70 Å along the [111] direction. The compositional modulation is associated with a reduction of the band gap by 130 meV, with respect to the random alloy. While segregation of the AlGaAs alloy has been seen previously, this is the first observation of segregation of AlGaAs grown on a (111) surface. The compositional modulation terminates abruptly at the boundaries of the (111) facet, forming abrupt lateral junctions in the AlGaAs layers grown on a groove.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Nq Composition and phase identification
68.35.B- Structure of clean surfaces (and surface reconstruction)
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors

Passivation of acceptors in InP resulting from CH4/H2 reactive ion etching

T. R. Hayes, W. C. Dautremont‐Smith, H. S. Luftman, and J. W. Lee

Appl. Phys. Lett. 55, 56 (1989); http://dx.doi.org/10.1063/1.101752 (3 pages) | Cited 36 times

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Reactive ion etching of InP with CH4/H2 mixtures leads to hydrogen passivation of near‐surface Zn acceptors but not S donors. Secondary‐ion mass spectrometry (SIMS) measurements of CH4/D2 etched samples show deuterium diffuses to a depth of 2000 Å in p‐InP (1.5×1018 cm−3) when etching at a rate of 520 Å/min and a temperature of about 80 °C. Acceptor passivation occurs to the same depth. For n‐InP, no donor passivation is observed, even though SIMS shows deuterium diffusion to a depth of 7000 Å. Annealing at 350 °C for 1 min restores carrier concentrations to near pre‐etched levels.
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71.55.Eq III-V semiconductors
81.65.-b Surface treatments
66.30.J- Diffusion of impurities

Reduction of Be diffusion in GaAs by migration‐enhanced epitaxy

Bijan Tadayon, Saied Tadayon, W. J. Schaff, M. G. Spencer, G. L. Harris, P. J. Tasker, C. E. C. Wood, and L. F. Eastman

Appl. Phys. Lett. 55, 59 (1989); http://dx.doi.org/10.1063/1.101753 (3 pages) | Cited 3 times

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Be‐doped GaAs layers were grown by the migration‐enhanced epitaxy (MEE) method at 300 °C. The MEE layers showed practically no electrical activation. Rapid thermal annealing on the MEE layers resulted in mobility and hole concentration comparable to those of conventional molecular beam epitaxy (MBE) layers grown at 600 °C. Secondary‐ion mass spectroscopy showed that the Be diffusion in annealed MEE layers was much smaller than that in conventional MBE layers, especially for highly doped layers. Raman spectroscopy and 4 K photoluminescence were also performed. The MEE method can replace the conventional MBE method for device applications which require high hole concentration with small diffusion.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
66.30.J- Diffusion of impurities
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Multiwafer growth of CdTe on GaAs by metalorganic chemical vapor deposition in a vertical, high‐speed, rotating disk reactor

G. S. Tompa, C. R. Nelson, M. A. Saracino, P. C. Colter, P. L. Anderson, W. H. Wright, and J. L. Schmit

Appl. Phys. Lett. 55, 62 (1989); http://dx.doi.org/10.1063/1.101754 (3 pages) | Cited 8 times

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Growth of CdTe (111) layers on GaAs (100) and GaAs (111) substrates by metalorganic chemical vapor deposition (MOCVD) has been investigated using a commercial, vertical, high‐speed, rotating disk reactor. Dimethylcadmium (DMCd) and diisopropyltelluride (DIPTe) were used as the growth precursors. The growth rate was measured over the temperature range from 308 to 402 °C. DMCd molar growth efficiencies greater than 50% are obtained for growth temperatures greater than 368 °C. X‐ray rocking curves for the (422) and (333) reflection planes of CdTe (111)<90 arcsec full width at half maximum were obtained at 380 °C for films on the (111) substrates. Scanning electron microscopy on cleaved wafers and infrared interference spectroscopy show edge‐to‐edge thickness uniformity to be 1.3%. The far‐infrared reflectivity was measured using a Fourier transform infrared spectrometer to obtain the TO phonon spectra. These data indicate that the thickness and dielectric constant of the CdTe is extremely uniform. Overall, the films obtained in this study are more uniform and of higher quality than the best films produced in a horizontal reactor using similar growth procedures.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.55.-a Thin film structure and morphology

NH3 as a photosensitizer in the epitaxial growth of Ge on GaAs by laser photochemical vapor deposition

C. J. Kiely, V. Tavitian, C. Jones, and J. G. Eden

Appl. Phys. Lett. 55, 65 (1989); http://dx.doi.org/10.1063/1.101755 (3 pages) | Cited 7 times

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The viability of ammonia as a sensitizer for the growth of epitaxial Ge on GaAs (100) by laser photochemical vapor deposition (LPVD) has been investigated. Specifically, NH3/GeH4/He (0.8/55.0/95 sccm, 5.5 Torr total pressure) mixtures have been irradiated by an excimer laser beam (ArF, 193 nm) in parallel geometry and for substrate temperatures (Ts) in the range 25≤Ts<400 °C. As evidenced by a more than an order of magnitude acceleration in the Ge film growth rate (factor of ∼33 improvement at 305 °C), even trace amounts of NH3 added to the gas stream efficiently couple the laser radiation to the Ge precursor (GeH4) without incorporating significant concentrations of N and H into the film. Auger, secondary‐ion mass spectrometry (SIMS), and x‐ray photoelectron spectroscopy analyses of the films show the nitrogen content to be negligible (<1%). Also, the slight amount of hydrogen detected by SIMS appears to arise from hydrocarbon contaminants rather than from the ammonia. Transmission electron microscopy studies demonstrate that films grown at Ts≥300 °C are epitaxial with an amorphous overlayer. Embedded within the amorphous matrix are Ge microcrystals which are textured, having their 〈112〉 axes parallel to the substrate normal. The beneficial effect of NH3 on the growth rate of LPVD Ge films is attributed to the photolytic production of hydrogen atoms which efficiently decompose GeH4 by hydrogen abstraction collisions.
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81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.50.Bc Processes caused by infrared radiation
82.50.Hp Processes caused by visible and UV light
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Defects in molecular beam epitaxy grown GaAlAs layers

S. L. Feng, M. Zazoui, and J. C. Bourgoin

Appl. Phys. Lett. 55, 68 (1989); http://dx.doi.org/10.1063/1.101756 (2 pages) | Cited 4 times

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Using deep level transient spectroscopy we characterized the shallow native traps in n‐type doped Ga1−xAlxAs layers (with x=0.30 and 0.36) grown by molecular beam epitaxy. A trap lying at 0.18 eV below the conduction band is detected which exists in large concentration within 0.2 μm from the surface and is responsible for the freeze out of free carriers at low temperatures.
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73.20.Hb Impurity and defect levels; energy states of adsorbed species
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.61.Ey III-V semiconductors

Well size related limitations on maximum electroabsorption in GaAs/AlGaAs multiple quantum well structures

K. W. Jelley, R. W. H. Engelmann, K. Alavi, and H. Lee

Appl. Phys. Lett. 55, 70 (1989); http://dx.doi.org/10.1063/1.101757 (3 pages) | Cited 21 times

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Experimentally determined maximum electroabsorption in GaAs/Al0.33Ga0.67As multiple quantum wells over the quantum well width range of 17–260 Å is related to the confinement of the electronic wave functions in the quantum well, increasing with enhanced confinement. However, for very narrow wells, this increase in maximum electroabsorption is diminished by strong broadening of the excitonic resonances due to phonon scattering, eventually leading to a peak value of 22 200 cm−1 at a 35 Å well width.
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78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
42.79.Hp Optical processors, correlators, and modulators
78.30.Fs III-V and II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
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