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26 Jul 1993

Volume 63, Issue 4, pp. 429-566

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Demonstration of colliding‐soliton all‐optical switching

Stephen R. Friberg

Appl. Phys. Lett. 63, 429 (1993); http://dx.doi.org/10.1063/1.110013 (3 pages) | Cited 7 times

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A colliding‐soliton switch that takes advantage of the conservation properties of interacting solitons is demonstrated experimentally. We show that the switch, which can operate as an optical demultiplexer or as a logic gate, responds to incoming signal solitons without altering them. This is a consequence of its quantum nondemolition measurement capabilities, and allows multiple operations to be performed with the same soliton. Operation at rates exceeding 250 Gbit/s should be possible.
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42.65.Pc Optical bistability, multistability, and switching, including local field effects
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks

Performance improvement in quantum well lasers by optimizing band gap offset at quantum well heterojunctions

B. Zhao, T. R. Chen, A. Shakouri, and A. Yariv

Appl. Phys. Lett. 63, 432 (1993); http://dx.doi.org/10.1063/1.110014 (3 pages) | Cited 3 times

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We analyze the influence of the band gap offset at the quantum well (QW) heterojunctions on the performance of QW lasers. It is shown that, in addition to the strain, optimization of the band gap offset also leads to improved performance in QW lasers, especially in enabling a simultaneous attainment of ultralow threshold current and high speed. The improvement stems from the reduction of state filling in the QW lasers since the asymmetry between the conduction band and the valence band structures in the optical confining region is compensated by the corresponding optimal band gap offset at the QW heterojunctions. The results provide general guidelines to the design of high performance of QW lasers as well as suggest applications to other active laser devices.
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42.55.Px Semiconductor lasers; laser diodes
78.66.Fd III-V semiconductors
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Strain effect on the optical nonlinearity in an InGaAs/GaAs asymmetric Fabry–Perot modulator

M. H. Moloney, J. F. Heffernan, J. Hegarty, R. Grey, and J. Woodhead

Appl. Phys. Lett. 63, 435 (1993); http://dx.doi.org/10.1063/1.110015 (3 pages) | Cited 9 times

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The effect of strain on the optical nonlinearities and operation of an all‐optical asymmetric Fabry–Perot étalon is investigated. A high reflectivity modulation of 60% is reported with a contrast ratio of 12.2:1 and insertion loss of 1.87 dB. High contrast is achieved through absorption matching requiring a thick active layer. The effect of a thick structure on the strain reduced saturation carrier density is measured. The saturation density is calculated to be a factor of 2.5 less than in a similar GaAs modulator, showing thicker strained devices still display the advantages of thinner structures.
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42.79.Hp Optical processors, correlators, and modulators
78.66.Fd III-V semiconductors
42.65.Pc Optical bistability, multistability, and switching, including local field effects

Small‐signal gain measurements in an electron beam pumped F2 laser

H. M. J. Bastiaens, B. M. C. van Dam, P. J. M. Peters, and W. J. Witteman

Appl. Phys. Lett. 63, 438 (1993); http://dx.doi.org/10.1063/1.110016 (3 pages) | Cited 2 times

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The net‐small‐signal gain of a molecular fluorine F2∗ laser pumped by a coaxial electron beam has been measured in gas mixtures of He/F2 and He/Ne/F2. A peak net‐small‐signal gain of 0.63 cm−1 has been measured in a mixture of He/Ne/F2 at a pressure of 8 bar and a pumping power density of 13 MW/cm3.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Influence of separate‐confinement layer band structure on the transport‐limited modulation bandwidth in quantum well lasers

T. C. Wu, S. C. Kan, D. Vassilovski, and K. Y. Lau

Appl. Phys. Lett. 63, 441 (1993); http://dx.doi.org/10.1063/1.110017 (3 pages) | Cited 8 times

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We analyze the influence of band‐structure design of the SCH region on the transport‐limited modulation bandwidth in quantum well (QW) lasers. By properly grading the SCH region, limitations due to physical‐space transport can largely be removed. Limitations due to intrinsic quantum capture (state‐space transport) then becomes the dominant one for GRINSCH QW lasers, though this, too, can be alleviated (but only completely removed) by proper band‐structure design.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking

Design and fabrication of asymmetric strained layer mirrors for optoelectronic applications

J. C. Bean, L. J. Peticolas, R. Hull, D. L. Windt, R. Kuchibhotla, and J. C. Campbell

Appl. Phys. Lett. 63, 444 (1993); http://dx.doi.org/10.1063/1.110018 (3 pages) | Cited 9 times

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The design of thin‐film mirrors is optimized for strained layer materials systems. It is shown that the use of asymmetric structures produces only minor loss in reflectivity per mirror period, while greatly extending the number of periods that can be grown in a defect‐free mode. As applied to the GexSi1−x/Si strained layer system, the net result is an enhancement of reflectivity, with 1.3 μm mirrors achieving peak values near 75%. The approach is applicable to other materials systems and should yield even higher reflectivities in situations where wider ranges in index of refraction are available.
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78.66.-w Optical properties of specific thin films
42.79.Fm Reflectors, beam splitters, and deflectors
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Nearly resonant two‐photon absorption of C60 thin film at 633 nm

Y. N. Han, W. J. Zhang, X. M. Gao, Y. B. Cui, Y. X. Xia, G. Gu, W. C. Zang, P. Yang, Y. W. Du, and D. Feng

Appl. Phys. Lett. 63, 447 (1993); http://dx.doi.org/10.1063/1.110019 (2 pages) | Cited 8 times

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We present an absolute measurement of a two‐photon absorption (TPA) coefficient of C60 thin film at 633 nm. Large values of β≊4.4 cm/W were determined. A nearly resonant TPA transition around the 3.76 eV absorption region was discussed.
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71.20.Mq Elemental semiconductors
42.65.-k Nonlinear optics
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.66.Db Elemental semiconductors and insulators

Photo‐optical liquid crystal cells driven by molecular rotors

Kunihiro Ichimura, Yuko Hayashi, Haruhisa Akiyama, Tomiki Ikeda, and Norio Ishizuki

Appl. Phys. Lett. 63, 449 (1993); http://dx.doi.org/10.1063/1.110020 (3 pages) | Cited 34 times

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Photochemical regulation of in‐plane alignment of a nematic liquid crystal is presented. A quartz plate surface was modified with 4‐hexyl‐4′‐hexyloxyazobenzene substituted with triethoxysilyl group through a spacer at the 2′ position to introduce the side‐on type azobenzene unit of the surface. A liquid crystal hybrid cell fabricated with the azo‐modified plate was irradiated with linearly polarized visible light for the n‐π∗ transition. This resulted in the in‐plane reorientation of the liquid crystal molecules to afford homogeneous alignment. Discussion is made on the mechanism of the in‐plane alignment regulation, and the concept of a molecular rotor is proposed.
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61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
42.79.Kr Display devices, liquid-crystal devices

High contrast asymmetric Fabry–Perot electro‐absorption modulator with zero phase change

J. A. Trezza, B. Pezeshki, M. C. Larson, S. M. Lord, and J. S. Harris

Appl. Phys. Lett. 63, 452 (1993); http://dx.doi.org/10.1063/1.110021 (3 pages) | Cited 6 times

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By analyzing the exciton line shapes of quantum wells, we can determine the wavelengths and biases at which they exhibit large absorption changes and zero refractive index changes relative to zero bias. To use this effect, we placed GaAs/AlGaAs quantum wells in the intrinsic region of a reverse‐biased p‐i‐n diode asymmetric Fabry–Perot modulator. We then developed a sample that could be post‐growth processed to optimize all relevant parameters. We used computer simulation to determine the exact post‐growth correction required and produced reflection modulators with 90% reflection change and zero relative phase change.
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42.79.Hp Optical processors, correlators, and modulators
78.66.Fd III-V semiconductors

Use of fullerene films as surfaces of uniform electric potential

J. B. Camp and R. B. Schwarz

Appl. Phys. Lett. 63, 455 (1993); http://dx.doi.org/10.1063/1.110022 (3 pages) | Cited 4 times

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Continuous fullerene films (85% C60, 15% C70) of thickness ∼10 nm have been sublimed on a metallic substrate previously coated with a 1‐nm‐thick Ge sublayer. The films show no surface potential variations when scanned with a Kelvin probe of 1 mV and 1 mm potential and spatial resolutions. Transmission electron microscopy reveals the fullerene films to be amorphous.
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73.30.+y Surface double layers, Schottky barriers, and work functions
73.61.Jc Amorphous semiconductors; glasses

Accurate monocrystal miscut angle determination by x‐ray diffraction on a wedge

M. Gailhanou

Appl. Phys. Lett. 63, 458 (1993); http://dx.doi.org/10.1063/1.110023 (3 pages) | Cited 3 times

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Semiconductor crystal miscut angles may be determined with high precision by a new method, based on the measurement of the Bragg angle shift for a highly asymmetric reflection. X‐ray diffraction on a cleaved wedge has the particularity that the asymmetry is different for the cleavage plane and for the surface whose miscut angle is to be determined. Therefore, a rocking curve gives rise to two diffraction peaks. The angular difference between the two peaks is very sensitive to the miscut angle for high asymmetry of the reflection relative to the measured surface.
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61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
81.10.Aj Theory and models of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation

Hydrogen incorporation in the early stages of hydrogenated amorphous silicon deposition evaluated by real time infrared reflectance spectroscopy

M. Katiyar, G. F. Feng, Y. H. Yang, J. R. Abelson, and N. Maley

Appl. Phys. Lett. 63, 461 (1993); http://dx.doi.org/10.1063/1.110024 (3 pages) | Cited 6 times

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We use real time, high sensitivity infrared reflectance spectroscopy to quantitatively study hydrogen incorporation during the growth of hydrogenated amorphous silicon by magnetron sputtering. For the range of deposition conditions studied (substrate temperature between 120 and 270 °C and H2 partial pressure between 0.1 and 1.0 mTorr, which result in film hydrogen content between 10 and 30 at. %), hydrogen incorporation reaches steady state for film thickness, d≳25 Å. Deviations from uniform growth for d<25 Å are attributed to plasma‐substrate interactions due to energetic hydrogen implantation tens of angstroms beneath the growing surface and changes in the surface area during nucleation and coalescence.
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81.15.Cd Deposition by sputtering
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
78.35.+c Brillouin and Rayleigh scattering; other light scattering

Growth kinetics of disk‐shaped extended defects with constant thickness

Scott T. Dunham

Appl. Phys. Lett. 63, 464 (1993); http://dx.doi.org/10.1063/1.110025 (3 pages) | Cited 10 times

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In this work, we derive a simple analytic expression for the growth rate of disk‐shaped extended defects which maintain their thickness as they grow. The analysis includes both the interface reaction and solute diffusion as limiting the growth rate. We consider both the surface energy and the matrix strain energy and assume a toroidal capture surface around the periphery of the disk in determining the rate of the interface reaction. We utilize a series of spheres to approximate a torus and thereby are able to derive a simple expression for the solute concentration near the periphery of the disk as a function of solute diffusivity and defect size.
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61.72.Nn Stacking faults and other planar or extended defects
61.72.Lk Linear defects: dislocations, disclinations
61.72.Bb Theories and models of crystal defects
81.40.Cd Solid solution hardening, precipitation hardening, and dispersion hardening; aging

Epitaxial lead zirconate‐titanate thin films on sapphire

W. Braun, B. S. Kwak, A. Erbil, J. D. Budai, and B. J. Wilkens

Appl. Phys. Lett. 63, 467 (1993); http://dx.doi.org/10.1063/1.110026 (3 pages) | Cited 14 times

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Pb(Zr1−xTix)O3 thin films covering the whole compositional range x=0 to x=1 have been grown for the first time on the sapphire (1102) plane using the metalorganic chemical vapor deposition technique. The films are three‐dimensionally epitaxial and exhibit single crystal properties. The structural transitions, examined by x‐ray diffraction, are shifted slightly from the bulk single crystal values. Ferroelectric P‐E hysteresis curves and the dielectric constant of the films were investigated using interdigitated electrodes fabricated by photolithography.
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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
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates

Influence of oxygen concentration and annealing on morphology and electrical properties of semi‐insulating polycrystalline silicon

S. Lombardo, S. U. Campisano, and F. Baroetto

Appl. Phys. Lett. 63, 470 (1993); http://dx.doi.org/10.1063/1.110027 (3 pages) | Cited 3 times

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Semi‐insulating polycrystalline silicon films, deposited by low‐pressure chemical vapor deposition on oxidized Si substrates at O concentrations from 2 up to 35 at. % O, have been annealed at 920 °C for 30 min. Transmission electron microscopy revealed the presence of crystalline Si grains. The average Si grain radius decreases with O content going from ≊15 up to ≊2 nm, while electrical resistance increases with O concentration of almost four orders of magnitude. We attribute the resistance increase at large O contents to the presence of SiO2 shells, two monolayers thick, covering the Si grains. At these large O contents a noticeable increase in Si grain size and electrical conductance is observed in samples annealed at 1200 °C for 30 min. These results can be interpreted on the basis of thermal instability of the oxide shells. This assumption is supported by observations of native oxide breaking against high‐temperature annealings.
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61.72.Cc Kinetics of defect formation and annealing
73.61.Cw Elemental semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Laser‐plasma deposition of diamond phase at low temperatures

Jayshree Seth, R. Padiyath, D. H. Rasmussen, and S. V. Babu

Appl. Phys. Lett. 63, 473 (1993); http://dx.doi.org/10.1063/1.110028 (3 pages) | Cited 8 times

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Diamond crystallites were deposited on single‐crystal (100) silicon substrates by the KrF (248 nm) excimer laser ablation of pyrolytic graphite in an argon rf plasma ambient. No external heating or seeding of the rf biased substrates was used. The rf plasma ambient caused surface restructuring of the silicon substrate, presumably via sputtering, which facilitated the nucleation of 0.01–0.15 μm diamond crystallites. The diamond cubic structure was confirmed by transmission electron diffraction analysis. However, the Raman 1332 cm−1 mode, characteristic of diamond, was not detected. The rf bias accelerates the ions in the laser‐induced plume and rf plasma discharge towards the substrate likely facilitate nucleation of the diamond phase on the restructured and roughened silicon substrate.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Measurements of barium photocathode quantum yields at four excimer laser wavelengths

M. D. Van Loy, A. T. Young, and K. N. Leung

Appl. Phys. Lett. 63, 476 (1993); http://dx.doi.org/10.1063/1.110029 (3 pages) | Cited 2 times

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The electron quantum yields from barium cathodes excited by excimer laser radiation at 193, 248, 308, and 351 nm have been determined. Experiments with different cathode surface preparation techniques reveal that deposition of barium film a few microns thick on a clean copper surface under moderate vacuum conditions achieves relatively high quantum efficiencies. Quantum yields measured from surfaces prepared in this manner are 2.3×10−3 at 193 nm, 7.6×10−4 at 248 nm, 6.1×10−4 at 308 nm, and 4.0×10−4 at 351 nm. Other preparation techniques, such as laser cleaning of a solid barium surface, produced quantum yields that were at least an order of magnitude lower than these values.
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79.60.-i Photoemission and photoelectron spectra
79.20.Ds Laser-beam impact phenomena

Preferred concentration enhancement of photobleachable defects responsible for 5 eV optical absorption band in SiO2:GeO2 glass preform by heating in a H2 atmosphere

Hideo Hosono, Hiroshi Kawazoe, and Ken‐ichi Muta

Appl. Phys. Lett. 63, 479 (1993); http://dx.doi.org/10.1063/1.110782 (3 pages) | Cited 12 times

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Heat treatment of a 5GeO2‐95SiO2 glass preform in a H2 atmosphere at 500 °C for 70 h increased intensities of an absorption band centered at 5 eV by a factor of ∼3. Intensities of photobleachable component, which is the precursor of UV‐induced Ge E′ centers and assigned to a neutral oxygen monovacancy, of the 5‐eV band were enhanced by a factor of ∼8 by heating. This increment is ∼3 times as large as that of UV‐unbleachable component, which is assigned to Ge2+ centers coordinated by two oxygens (neutral oxygen divacancy).
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42.70.Ce Glasses, quartz
61.72.J- Point defects and defect clusters
78.30.Hv Other nonmetallic inorganics
78.40.Ha Other nonmetallic inorganics
81.40.Tv Optical and dielectric properties related to treatment conditions

Quantitative characterization of epitaxial superlattices by x‐ray diffraction and high resolution electron microscopy

Eric E. Fullerton, Wei Cao, Gareth Thomas, Ivan K. Schuller, Matthew J. Carey, and Ami E. Berkowitz

Appl. Phys. Lett. 63, 482 (1993); http://dx.doi.org/10.1063/1.110030 (3 pages) | Cited 6 times

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Quantitative x‐ray diffraction (XRD) and high resolution electron microscopy (HREM) have been applied to the analysis of an epitaxial CoO/NiO superlattice. This example shows that the qualitative information determined directly from a XRD spectrum or HREM image is limited and can even be misleading. However, by a combination of quantitative intensity measurements and structural modeling, a detailed quantitative characterization of the superlattice structure is possible.
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61.05.C- X-ray diffraction and scattering
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)
68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

In situ solid phase epitaxial growth of C49‐TiSi2 on Si (111)‐7×7 substrate

Chi Kyu Choi, Soo Jeong Yang, Jai Yon Ryu, Jeong Yong Lee, Hyung‐Ho Park, Oh Joon Kwon, Yong Pak Lee, and Kun Ho Kim

Appl. Phys. Lett. 63, 485 (1993); http://dx.doi.org/10.1063/1.110007 (3 pages) | Cited 4 times

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C49‐TiSi2 film was grown epitaxially on Si(111) substrate by depositing Ti film on Si(111)‐ 7×7 surface followed by in situ annealing in ultrahigh vacuum. The deposition was monitored by means of reflection high energy electron diffraction as a function of the thickness of Ti film. The best result for the growth of epitaxial C49‐TiSi2 was obtained from the Ti(30 ML)/Si(111)‐7×7 sample which was annealed at 650 °C for 20 min. Images of cross‐sectional high resolution transmission electron microscopy shows that the silicide/silicon interface is shown to be clear and flat. The orientation relationships are TiSi2[211]∥Si[011], TiSi2 (120)∥Si(111) without misorientation angle. Almost the whole area of the TiSi2 layer is revealed as an epitaxial C49 structure.
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81.15.Np Solid phase epitaxy; growth from solid phases

Raman scattering from oval defects in GaAs epilayers

P. K. Khulbe, P. S. Dobal, H. D. Bist, S. K. Mehta, R. Muralidharan, and R. K. Jain

Appl. Phys. Lett. 63, 488 (1993); http://dx.doi.org/10.1063/1.109982 (3 pages) | Cited 4 times

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Micro‐Raman investigations have been carried out at various spots in and around oval defects in epitaxially grown 〈100〉 GaAs wafers. Changes in the crystalline orientation have been observed within the oval defect structure as compared to the normal region. However, the crystalline quality of these defects remain equally good. These oval defects also possess a deviation in stoichiometry, corroborating to the conclusions of other studies.
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68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.30.Fs III-V and II-VI semiconductors
78.66.Fd III-V semiconductors

Electroluminescence at room temperature of a SinGem strained‐layer superlattice

Jesper Engvall, Janos Olajos, Hermann G. Grimmeiss, Hartmut Presting, Horst Kibbel, and Erich Kasper

Appl. Phys. Lett. 63, 491 (1993); http://dx.doi.org/10.1063/1.110780 (3 pages) | Cited 33 times

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We report for the first time on room temperature electroluminescence in the region 1.3–1.7 μm from a strain‐adjusted Si6Ge4 superlattice. These results, together with photoluminescence, short‐circuit photocurrent spectroscopy, and voltage‐intensity and current‐intensity measurements indicate that the observed electroluminescence consists of two emission bands which are believed to be caused by defect and interband recombination processes.
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78.60.Fi Electroluminescence
78.66.Db Elemental semiconductors and insulators

Low‐voltage vertical‐cavity transmission modulator for 1.06 μm

I. J. Fritz, T. M. Brennan, B. E. Hammons, A. J. Howard, W. Worobey, G. A. Vawter, and D. R. Myers

Appl. Phys. Lett. 63, 494 (1993); http://dx.doi.org/10.1063/1.109983 (3 pages) | Cited 4 times

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We present results on the first all‐semiconductor, vertical Fabry–Perot‐cavity optical transmission modulator. This device combined mechanically stable strained and unstrained (In,Al,Ga)As multilayers to achieve operation at 1.06 μm. Transmission‐mode operation allows the resonant wavelength of the cavity to be finely tuned by varying the angle of incidence, providing, for the first time, a means of compensating for small inaccuracies in growth parameters. Using the modulator in double‐pass operation with a corner‐cube retroreflector, we demonstrate a tunable reflectance modulator with a fractional modulation of 25% at 3‐V bias, suitable for applications in free‐space communication.
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42.79.Hp Optical processors, correlators, and modulators
78.66.Fd III-V semiconductors

Optical properties of Si/Si0.87Ge0.13 multiple quantum well wires

Y. S. Tang, C. D. W. Wilkinson, C. M. Sotomayor Torres, D. W. Smith, T. E. Whall, and E. H. C. Parker

Appl. Phys. Lett. 63, 497 (1993); http://dx.doi.org/10.1063/1.109984 (3 pages) | Cited 16 times

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Nanometer‐scale wires cut into a Si/Si0.87Ge0.13 multiple quantum well structure were fabricated and characterized by using photoluminescence and photoreflectance at temperatures between 4 and 20 K. It was found that, in addition to a low‐energy broadband emission at around 0.8 eV and other features normally observable in photoluminescence measurements, fabrication process induced strain relaxation and enhanced electron‐hole droplets emission together with a new feature at 1.131 eV at 4 K were observed. The latter was further identified as a transition related to impurities located at the Si/Si0.87Ge0.13 heterointerfaces.
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78.66.Li Other semiconductors
78.30.Hv Other nonmetallic inorganics
78.55.Hx Other solid inorganic materials
81.65.-b Surface treatments

Multiple dislocation loops in linearly graded InxGa1−xAs (0≤x≤0.53) on GaAs and InxGa1−xP (0≤x≤0.32) on GaP

J. C. P. Chang, T. P. Chin, C. W. Tu, and K. L. Kavanagh

Appl. Phys. Lett. 63, 500 (1993); http://dx.doi.org/10.1063/1.109985 (3 pages) | Cited 18 times

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We report transmission electron microscopy studies of dislocation structures in two lattice‐mismatched III‐V systems, InxGa1−xAs (0≤x≤0.53)/GaAs and InxGa1−xP (0≤x≤0.32)/GaP, grown by gas‐source molecular beam epitaxy. Multiple dislocation‐loops, extending from within a linearly graded buffer layer to deep inside the substrate, were observed in both systems. All dislocations in each set of loops consisted of 60° dislocations with the same Burgers vector on a similar {111} glide plane. The density in the graded buffer and the substrate was estimated to be 2×109/cm2, and their appearance was associated with low threading dislocation densities and good optical quality in material grown on top of the buffer layer, InP/In0.53Ga0.47As on GaAs or In0.32Ga0.68P on GaP.
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61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
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